To add to this discussion here are two mounting systems I have found, one does not seem to work with BMW and the other does except for the 335I with premium package, not sure what the Rear view mirror changes with that package.
Has anyone found any other or know what works on the 335I
http://www.countryjoycrafts.com/350Z/minimount.htm
http://store.nexternal.com/shared/St...t=products.asp
Also, I found this great wiring kit and the price is fair.
http://www.safe-n-sound1.com/Valentine.html
I have used the one with the mute button and it works great.