Added mine last night, took maybe 30 minutes. Used the mini aux (Part Number 82 11 0 153 367) ordered from ECS tuning for $40 shipped. You cannot control it from the wheel/cd, but for $40 ill take it!
I would recommend watching this video to see how the vents come out:
Instructions here:
http://www.zpost.com/forums/showthre...80#post9819780
Aux here:
http://www.ecstuning.com/ES194874/?g...VzUaAn0b8P8HAQ