I bought a 2009 Z4, in April. After delivery, I found the car only had (S693) preparation for Sirius Satellite radio. This means the actual receiver is not installed, but the car is supposed to be wired for the radio receiver, antenna, and possibly the head unit. I checked with a installer near my home in Bow, NH, and they know nothing about installing this radio in a Z4, and could not find any documentation on the install. I did acquire a radio from a used parts house. The radio is supposed to mounted in the trunk. I looked where the battery is located, and could not find any location for the mount, nor vacant plugs. I don't want to start tearing out lining in the trunk since I don't have a clue where to start. Also, I cannot find a Bentley, Chiltons, nor Hayes manual for the 2009 Z4. I also think the radio head unit may need to be replaced too, it is BMW Professional (663), with HiFi System Professional DSP (S677). So, any help with this situation will be appreciated.