I have not installed one myself. However, it is my understanding that you/installer would have to remove the PCM to connect the unit to the MOST (not a big to-do). You would also need to fish the microphone either to the driver (A) pillar or the homelink console.

 

I have installed one on my cayenne didnt really like it as people said they couldnt hear me that well, i have full compatibility with my PCM 2.1

 

parrot makes a neat aftermarket bluetooth device that can make and take phone calls AND stream music from a PDA device to your car. pretty cool