I wanted to give an update and display some pictures of the install of the Soundgate KBMWSIR adaptor for use in my 2001M3. It really could not have been easier. I just used the existing wiring for the Aux CD changer that I found in the trunk and hooked them up to the new adaptor. Ran power from the battery to the Kenwood tuner and mounted the antenna on the rear window deck. I have complete control of the new Sirius tuner using my factory BMW head unit plus the steering wheel radio controls also work for volume and channel selection. It operates just as advertised except that I can only see on my display the Sirius Channel number without any extra text. This really is a non issue for what the upside is when compared to mounting a separate tuner control and FM modulator. The complete install only took around 2 hours. I managed to use the space in the truck where normally the spare tire would go. Seemed like a good place to mount the components and totally hide the install. There seems to be enough free air space that over-heating the turner is not a factor. I am going to install a thermocouple on the tuner to double check the temperature rise on tuner body however I have just come back from a 1 hour drive and when I checked for heat is was non-existent. Anyone thinking of installing satellite radio should look into this adaptor. I ordered it directly from Soundgate and the cost was around $130 delivered to my door. Soundgate also has another adaptor like this one for use on the Pioneer XM system.
http://photos.yahoo.com/jkemmerly