I don't usually post but I just finished installing an MHI bluetooth setup in my wife's 2006 R171 and felt I should share with anyone else interested in trying this install. Thanks to the information I found here and at other Mercedes forums I was able to determine part numbers and install instructions. I puchased the core kit (less linear compensator), completer kit, and an MHI bluetooth adapter on the web. It took me about an hour to install the MHI plug in the center console plus another 1-1/2 hours to remove the equipment carrier in the trunk, install the MHI and wiring and put everything else back together. The only real problem I had was figuring out the "tricks" to disengage a few of the electrical connectors. Other than that it was a piece of cake. I then installed the Bluetooth adapter, fired it up and everything works great. Using a v3 Razr, the phonebook downloads, I can scroll the phonebook, make calls, answer calls and hang up using the steering wheel buttons. Interesting enough, the signal strength accurately appears on the Audio 20 screen. I purchased the latest release of the bluetooth puck and MHI which may account for this unexpected bonus. Also, I have not had the car Star Coded and am beginning to think I will not need to take it to dealer for this added step. Maybe it was coded to include a phone from the factory. No sure but everything included TelAid is working properly. The whole deal cost me about $1,300 which is about half of what my dealer wanted to do the install. It was fun, not overly difficult, and certainly worth a few hours of my time. I am just an average guy with no special training in auto electronics. If anyone needs part numbers or help with the install let me know.