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OBC retrofit

Discussion in 'E30 (1984-1993)' started by az3579, Feb 28, 2009.

    Autohaus guest

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    Hard to believe that installing a OBC to your E30 is causing so many problems. I hope it all works out in the end. If not, there is always Kamal!
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    az3579

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    I'm sure the harness connections are good because all of the functions of the OBC work, and the buttons light up.

    I called the dealership to try to order a lightbar to see if that was the problem, but their electrical parts aren't returnable. , so I want to confirm before I order anything.

    I will try to voltmeter the leads if I could fit them in there to begin with...
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    Brian A

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    Light bar test #00003

    If you still have doubts about the light bar, you can always hook up the two terminals to a battery (4 AAs put in series would be enough) to see if the light bulbs glow. Don't exceed 12v though.
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    az3579

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    You're a genious... can't believe I haven't thought of that. 4 years of electronics in trade school and I remembered not a damned thing...

    Now to find 4 AA batteries; what a challenge that can be!


    EDIT: Used a 9v battery (says 10v max on the circuit board). Unfortunately, the light bar did light up, so that means there's something wrong with my OBC. :(
    What a waste of my life...
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    Brian A

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    What is that?

    Could be worse; at least its interesting.
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    az3579

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    Sorry, I had a long and confusing day so my spelling took a back seat. Could be worse, eh genius? :p


    The bright side is that I don't have to send back my light bar...
    Bad news is that I have to get a new OBC. Anyone have one they want to get rid of?
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    granthr

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    Botond: I might have one that I can spare. Also do you know which coding plug you need (p/n)? I will look when I get home. It won't be perfect and the light bar is burned out, but it should work fine otherwise.

    This has been a busy week for me, so I have not had time to check in here. I installed the full function obc into my 318i. Replace the euro analog clock I did have in it. Still kind wish I still had that in, but I really like the temp gauge. I also had trouble getting the light bar to work. It was working intermittently. So when I had the dash apart for another reason I thought I would unplug the light bar a couple times to see if I could get the connection better. Well that was a bad idea. Also shame on me for putting everything back together before testing. The result was a light bar that no longer worked. I then bought a new one from BMW, reinstalled and it does work 99% of the time, but there are occasions that it doesn't. Very strange. Lets just say I am very good a taking apart and reassembling my dash now.
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    granthr

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    Botond, pm me your address and I will mail it to you.
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    az3579

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    Actually, I got a hold of three OBC's yesterday while I was picking up an 'is' spoiler. I tore down my dash and installed all three on the spot to see if any of them would work and they all worked, but none of them had the display illuminated. I don't know if all three had bad lightbars, and unfortunately I didn't have my "brand new" lightbar with me; it was over 60 miles away. What a bummer.

    I brought all three of them home and will be testing the lightbars with a 9v battery later today like I did with my new one. Hopefully they will all test bad so I have hope if it just being bad lightbars.

    EDIT: I tested all three lightbars with a 9v battery and none of them lit up, so my current guess is that if I pop in my new lightbar into one of them then I will have a working OBC!

    Will keep you posted.
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    Brian A

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    Congratulations and best wishes!

    I have been following your adventures here with interest. I too am foolish enough to be considering replacing the 6 button computer on my 1991 318i. Where did you find instructions on how to install the 13 button computer? What is the total parts list required? Is it too much trouble for what it's worth? (Do you have any left over harnesses, OBCs, lightbars you want to get rid of?)
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    az3579

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    Does anyone know what coding plugs will work for my car? I've done searches and can't seem to find consistent part numbers for which plug I need for the OBC.

    The part numbers that I found end in:
    373 698
    381 795
    381 320

    Of the total 4 OBCs that I have in my possesion, the part plugs that I have are:
    381 793
    381 792
    375 826
    375 814

    Would any of these work with a 325e built in 9/86? Would any of these work if I swap a s50 (I'm firming up on a deal)?

    The one I have in the car now probably isn't the right one because yesterday it computed me averaging 35mpg on a trip. Not with my right foot, that's for sure. (381 792)
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    Brian A

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    A dealership should be able to tell you which one you need based on your VIN.
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    az3579

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    Update:

    Just after posting, I found a list of the coding plugs for the different models:

    318i 3-3 TYP 65-81-1-376-027
    325e 3-8 TYP 65-81-1-373-698 84-9/86
    325e 3-1.4 TYP 65-81-1-381-795 9/86-9/87
    325e 3-1.4 TYP 65-81-1-385-941 9/87-
    325i 3-1.2 TYP 65-81-1-381-793 up to 9/87
    M3 3-1.1 TYP 65-81-1-381-792
    528e 5-8 TYP 65-81-1-375-814 85-87
    528e 5-1.3 TYP 65-81-1-385-031 88+
    535i 5-6 TYP 65-81-1-375-826
    M5 6-4 TYP 65-81-1-375-812
    635CSi 6-2 TYP 65-81-1-375-021 85-87
    M6 6-4 TYP 65-81-1-376-208
    735i 7-4 TYP 65-81-1-375-823 85-87

    So I've determined with certainty that I need the one ending in 381-795. Problem is, I have 792 (for an E30 M3) and 793 (for 325i) but not 795, which I need. The closest I found that I do have is 814, which is for the 528e. That will do for now. The only thing I expect to be off is the Range calculation, which I don't too much care about.

    And, the good news is that I found a working candidate. The bar bar works beautifully and I can now see my display without using my iPhone to light it up!

    The car is now back together and the problem is solved. Now my currently dilemma; the antenna grommet being a pain to install, but that's a story for another day. :)


    Thanks everyone for your help!
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    granthr

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    Botond:

    For the grommet, boil water on the stove. Put the the grommet in a travel coffee mug. Pour the boiling water into the mug and put the lid on. Take out to the car and with the grommet all soft from the hot water quickly attempt to put the grommet on while still hot. Don't burn yourself!!! :) Put back in hot water if it cools off before you get it in. It is much easier if your remove the whole power antenna assembly first. Put the grommet in and then the assembly back in.

    Regarding the coding plugs, do you have the one for the 318i? May I have it if you do? I have a 373-698 if you want it. I am not sure which one is in my car.
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    granthr

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    Brian:

    It is not too hard to install the larger 9 button obc. It just takes patience and with what I know you have done, I think you can do it just fine. It will require removing the gauge cluster, Radio/HVAC plate, and center console. If you have a six button then the temp gauge is already wired for you. Just be careful when putting the wireing loom in. Just run it where the existing wiring harness is. Take care with the wire straps. They do come undone without breaking if you take care.

    This is what you will need.

    Large OBC
    OBC Control Unit
    Wiring Loom/harness
    Gone/chime (you might already have)
    Turn signal stalk, for the cool remote control!
    Alarm buzzer, (if you want this, I didn't install it, goes in engine bay)
    Temp sensor, (You should already have this)

    To get all this you can try a number of sources. I would start with your local junk yard, advertisers in Roundel, then ebay, and place an ad in markerplace here and Roundel. Expect to pay between $50 and $100 for everything.
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    granthr

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    Botond: Where did you get that list of p/n for the coding plugs? Real OEM doesn't list 9 button OBC for some US models, all 318i/is for instance. But does for Euro models, but I got a different p/n than you have listed.

    Thanks!
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    az3579

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    After that post, I had to drop someone off (it was already dark) and I realized that I forgot to migrate the perfect bulb for the keypad lighting to the "new" OBC. Looks like I'll be doing this ALL OVER AGAIN TOMORROW. :mad:

    Grant,
    I have multiple coding plugs, but none of them are for a 318i. I do have one for an M3, though, but I wouldn't advise using it as the engine, fuel tank, and other things are different.
    I have coding plugs for: E28 M5 or 535is (65 81 1 375 826), E30 M3 (65 81 1 381 792), E28 528e (forgot part # - currently installed, and I'm using this one now), and an E30 325i (65 81 1 381 793). If anyone needs any of these, let me know.

    That coding plug that you have is for a 325e, but for a model with what I think is a smaller fuel tank. I do know that there was some kind of change between the early 325e models and my 87 because I have two different coding plugs listed for my build date 9/86, one of which is the earlier one (yours) and one that's later (ending 795).


    Brian,
    It's not really a hard thing to change the OBC, it just takes lots of time. I remember reading your article on iPod integration in Roundel and thought "boy I'd like to make an article - if I wasn't so incompetant". This project just requires you to be very careful, as you're dealing with old plastics and materials that can break easily.

    A rundown of the swap (prepare a nighttime snack/drink and reading glasses as this will take a while):

    The kit consists of the 13-button OBC (required),
    * wiring harness (required) [not sure of part #]
    * turn signal stalk with relay (optional) [keep in mind there is a separate stalk for cars with airbag and those without]
    * relay (part# 65 81 1 373 726 - I have NO idea what this part does and have not installed it) (optional)
    * new light bar (pretty much required - almost every OBC will come with a burned out light bar). You can get away with just buying a new bulb assembly as opposed to the whole housing + bulbs that I bought from BavAuto. Part # for the bulbs is: 62 11 1 368 299
    and new bulb for the keypad illumination [standard 1.2W / 12V bulb you can find in the parts store]

    I also recommend you change your center illumination bulbs "while in there", which are also 1.2W / 12V bulbs. You will need two of these.

    I found that you do not need to remove the battery lead to do this swap. Nothing was harmed when I did it with the battery still connected.

    Steering Wheel
    You should begin by installing the wiring harness to set the stage for the swap. Begin by taking off the steering wheel (pry out the emblem in the middle if yours is so equipped) as this would provide easy access to swapping the stalk and taking out the instrument cluster. My steering wheel uses a 21mm nut, yours may be different. After you take the nut off but BEFORE you take the steering wheel off, mark the inside of the wheel and the steering column so that you could properly align the two when reinstalling.

    Instrument Cluster
    Once the steering wheel is off, you need to take out your instrument cluster. For this, you'll need to drop the kick panel surrounding the steering column by turning the (3) quarter-turn screws that hold it in place. This will provide you access to the two nuts you need to remove the plastic surround with. This is the surround that goes just above the steering column and under the instrument cluster. The nuts are located on the other side of this plastic piece, and there is one on each side of the steering column. To get a better idea of where they are, you will need to poke your head inside and look for two knurled silver nuts that are a PITA to remove (at least for me it was the first time I did it [I never put them back]). Once removed, just pop off this plastic piece to reveal some screws holding in the bottom part of the plastic surround that goes around the instrument cluster. Remove these screws (there should be 4) and look at the top part of this plastic, above the cluster. There should be two more screws, both at the top, that you need to remove. Once this plastic surround slides out, you will see the instrument cluster itself. There are two tabs, left and right on the top that you will see, that are held in place by screws. Take out the screws. At this point, I recommend you put some kind of cloth on the steering column to prevent scratching the cluster's front.

    To pull the instrument cluster out, pull a little bit on the tabs so that they are dislodged from their positions and lightly pull forward and down on the instrument cluster so it tilts outwards. Once out, the faces of the gauges should be facing the steering column, with the connectors facing upwards and visible to you. Disconnect the three wiring harnesses (yellow, blue, and white) by using a screwdriver to push the black tabs up and pulling the connectors off. Instrument cluster is now out.

    Center console and handbrake surround (not required)
    This section isn't required, but will make life easier when trying to reinstall the center controls in the dash, and I recommend doing this as it is easy enough not to be a pain.

    Start at the rear of the handbrake surround. Take out the rear ashtray and disconnect any lighting if applicable (mine wasn't connected). There is a plastic nut in there holding the surround in place. Use a 10mm socket to take it out. The whole surround slides a bit backwards, and to get it off you'll have to slide the handbrake boot off the handbrake. You might have to put the car in 1st, 3rd, or 5th gear to get the thing out as it will get caught in the shifter as you slide it forward. Once out, proceed to the shifter surround.

    Pull off the shift knob and take out the shift boot and insulation if you still have it. Pry out the window switches by reaching in and pushing them out of their holes and disconnect the switches.

    On either side of the surround, down in the footwells, there is a quarter-turn screw holding the surround to the center of the car (sorry for the lack of good description). Turn these screws and taken them out. Go back to the shifter area and take out the plastic nut in the shifter compartment. This also uses a 10mm socket.

    At this point, you should be able to pull the entire surround back and up. Disconnect the cigarette lighter bulb and power wires and set the surround aside. Your center section should now look like a race car's, with only carpet left!

    Center switches and OBC
    This is where we get to the OBC. First, take out your old 6-button OBC by prying the plastic surround off the OBC with a thin flatblade screwdriver. Once off, you'll see two tabs on the top and bottom. Use these tabs to remove the OBC from the dash. Disconnect the wiring harness by flipping the black lever. Unfortunately, this will be the last "easy' OBC disconnecting; the 13-button one is a PITA.

    Pry out and disconnect the top switches (rear window defrost, hazard, circuit breaker ('88 MY and earlier), and audio fader switches. There are two screws holding the plastic bezel in place, located in the top part of the second and fourth window-switch positions (from left to right). Use a flashlight and you will see them. They are small-headed but long screws. Take these out.

    Removal of the radio is not necessary for the OBC swap, but if you have an aftermarket radio, remove the faceplate and bezel to avoid damage. If you plan on replacing the center illumination bulbs, then you must remove the radio.

    Pull off the temperature control knob, the three slider control knobs, and the blower knob. Take a very thin flathead screwdriver and pry off the plastic cover that has the little drawings on it (for the HVAC controls, surrounds the three sliders). This will reveal four phillips screws. Remove these.

    Under the entire HVAC control unit, there are two screws on either side (left and right) that, along with the help of clips, help hold the HVAC controls firmly to the center of the dash. If you removed the handbrake console and shifter console, then you did yourself a favor; look at where the top of the cigarette ashtray would be (you wouldn't be able to fit your head here if you didn't remove the consoles) and you'll see openings on the left and right. In these openings are the screws that hold the HVAC controls into the dash. Remove these screws.

    At this point, the entire assembly should now pull forward, and by entire aseembly, I mean the assembly that holds the radio, switches, HVAC controls, and OBC. Pull this assembly forward so you could access the area where the OBC was installed. You'll notice the actual HVAC controls/unit should stay put, and only the plastic surround/assembly will slide forward.

    Look where the OBC should be. You'll see a black plastic piece screwed into the plastic assembly. Remove these four screws and take out this plastic piece. You should now be able to install your 13-button OBC into that spot, using the four screws you just removed from that plastic bracket. Before screwing it in, this is the time to change the bulb for the keypad illumination in the OBC (you'll see the bulb holder on the back of the unit) and the light bar. For the bulb, just use some pliers and twist the holder and pull out. For the light bar, use the pliers to pull the white tab on the side of the unit. Take off the circuit board from the white housing and put in the new bulb bar (if you ordered just the bulb bar), or if you ordered the entire housing with bulbs like I did from BavAuto (65 81 1 375 461), then just pop that new badboy in.
    Make sure you have the correct coding plug for your car, otherwise your range and possiblly mpg calculations will be off.

    Install the OBC into the OBC spot using the four screws you removed the plastic bracket with but do not push the entire assembly back just yet. At this point, the wiring harness needs to be installed.

    Wiring harness
    Look for the wiring harness with the green connector that you disconnected from your 6-button OBC and follow it through its routing. You'll notice that the harness is held in place by zip-tie looking plastic that lines the inside top of the dash. Be very careful as this plastic is very old and it will break, like it did with me, so don't expect to reuse it. I used some velcro to hold the cable bundles together.

    You'll follow the wiring harness until it reaches the instrument cluster section. The yellow connector that plugged into the instrument cluster is also attached to this harness. Take it out of the cable organization and keep following the harness to the left of the instrument cluster. At this point, I gave up in trying to take the old harness out because the next cable tie junction was way too far in and my hands were too big to fit in there. As a result, I just bundled the harness together, velcroed it and tucked it away so it wasn't in the way. If you do decide to go on, you'll see what I'm talking about. Once you get that "junction" to release the harness, continue down into the driver's footwell, where the harness continues. As I did not remove the old harness, I do not know what else this harness connects into, but it should be a temperature sensor connector (one or two pin, with a white connector housing). Here is a list of connectors on this wiring harness. This description is from strictlyeta.net's article on this procedure (http://www.strictlyeta.net/technical/obcretrofit.html):


    So, install your new wiring harness, routing it the same way that the old one was. The yellow connector should end up in the instrument cluster well, the green connector should end up where the OBC is installed, the white connector should end up in the footwell somewhere where the mess of wiring is, and the blue connector should end up there as well, under the steering column.

    Turn signal stalk and relay (optional)
    Remove the bottom plastic cover for the steering column by taking out the two screws holding it in. You should see these two phillips screws where the steering wheel would otherwise be covering it. The screw heads are facing upwards.

    There are two more long screws holding the cover in place. Look on the bottom of the cover and you'll see a long horizontal opening. Look in here and you'll find your two screws. Remove these and the cover to expose the wiring for the turn signal stalk.

    The stalk itself is screwed to the steering column by two screws that you'll see when you remove the cover. There is an additional screw that is used to screw the grounding wire to the column, which you will also see. Unscrew these screws and remove the turn signal stalk, disconnecting the connector with the brown/yellow wiring (maybe your colors will be different). This is a "you'll see when you do it" section. You can leave the relay attached to the turn signal stalk (black box) or attach it to the "new" one if it doesn't have one. They are the same part number. I used the new stalk's relay because the sound was slightly different, deeper. I liked it enough to use the new one!
    The old stalk will have a wiring harness that connects into the white plastic assembly of connectors that are attached together. You'll see when you do it. The way you "disassemble" this plastic orgy of connectors is by sliding them on or off (they don't "detach", they slide). Once you slide off all the connectors off from each other, remove the stalk along with harness. Install the new stalk with harness the same exact way in reverse order as you removed the old stalk. There is an extra connector though (blue) that you will plug into the blue connector in the OBC harness that you dropped down.

    Now's the time for you to install that black box relay I mentioned earlier (I have no idea what it does). I do not know where it mounts and I do not know what connects into it, so you're on your own here.

    Once everything's connected with the stalk (be sure to screw in the grounding wire where the old one was screwed in!), you can reinstall the steering column cover.

    Now's the time for you to install that black box relay I mentioned earlier (I have no idea what it does). I do not know where it mounts and I do not know what connects into it, so you're on your own here.

    Reconnecting everything
    Now that the harness is in place, you can reinstall the instrument cluster, plugging in the white connector, blue connector, and the new yellow connector from the new harness. Installation is reverse of removal, and take special care not to break off the mounting tabs from the cluster. Try to install the cluster the same way by tilting it back in. You will have to play with it for it to go back in properly. You will also have a very hard time reinstalling it if the plastic zip tie things broke off inside, because the wiring harness must be routed above the cluster for it to fit properly. If the plastic ties break off, good luck trying to mount the harness to the top. I used velcro to hold it up while I installed the cluster. You can put back all the screws and trim except for the black plastic cover that goes right over the steering column. Install this last.


    Please, please, PLEASE test the lighting to make sure everything works properly. Turn the key to ignition II and test the functionality of the OBC and turn on the lights to make sure your light bar lights up and the keypad illuminates.

    As for the center controls, you can push the entire assembly back, making sure to line up the HVAC sliders into their "tracks". If you want to install new illumination bulbs, do it before you push everything back. One bulb is located on the bottom right in plain sight, and the other is located just under the radio on the left. If you do these bulbs, you will have to remove the radio to get to the left bulb.

    When pushing the entire control assembly back, make sure to have the sliders for the HVAC controls correctly line up in their "tracks" with the plastic bezel because otherwise you won't be able to push the plastic assembly back properly. When the sliders properly stick through the plastic bezel, put back the four screws that you removed. This will hold the entire thing together and keep it from falling apart on you. While pushing the assembly back, take care not to allow the connectors for the hazard switches etc. fall in behind the radio, otherwise you'll never get them out without taking it apart again. Reinstall the two bottom screws that you can only see from the shifter area, and then the two thin and long screws along the top of the bezel (remember, 2nd and 4th switch positions). Reinstall all switches and reinstall the faceplate for the HVAC controls before putting back the control knobs. If there's anything I forgot, reinstall it.




    *phew*
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    Brian A

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    Holy Heck! You have a massively good memory. This is excellent documentation. Thank you for doing the documenting because it will be useful for many people after you.


    Perseverance is a gift.


    We're all incompetent; just some of us are too dumb to feel discouraged. Seriously, there are plenty of editors out there to reject your work; why reject yourself before you try? Ninety percent of achievement is just showing up.
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    az3579

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    I'm usually too lazy to start projects like this, and when I do, I forget to take pictures or to even bother memorizing things. :p

    Since I'll be taking most of it apart again today, I'll take pics of the actual OBC swap. I won't be disassembling the steering column or instrument cluster again though...



    I forgot to mention -

    Grant, I got the grommet on, though in a strange way. I don't think I did it right, but it seems to be staying put. I put it in from the top and I used a very thin screwdriver to tuck the lip of the grommet into the hole. It seems like it's staying put, but if I was to touch the grommet from the underside then a part of it would pop out and eventually the rest would as well. I took out the old power antenna because it's a piece of garbage and just filled the hole by putting in a dime to cover the opening. :D
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    Elkoholic

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    Now THAT'S classy! I think the value of your ride just went up...by a whole dime...

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