Last week a friend was getting out of the back seat of my 325ci. when getting out a noticeable squeak came out of rt rear corner. I have not been able to get under the car yet. I do not hear it when driving. The only way to reproduce the sound is to put my body weight down on the rear corner. ant thoughts?
Rear shock mounts in many BMW's can be almost notoriously short-lived or failure prone... perhaps the pads the springs sit on wearing through? Look up the rear suspension, etc. on realoem.com and see if the parts diagrams might obviate a few potential culprits. Otherwise, get the sound to repeat, narrow down as much as possible where it's coming from, possibly resort to automotive stethoscope, to whatever degree you can pinpoint it should get you closer to finding the cause.
I just encountered the same thing in my '05 325i. The noise goes away when I release the parking brake, so it's most likely that the tension in the cable when the brake is engaged is causing it to contact something. Given that, it's a low-urgency item. I'll pass along what I find when I've had a chance to look into it further.
