I thought I mentioned this earlier, but I guess not. Getting back to Chris's original request, have you looked into Bluetooth audio receivers for your car stereo? That would eliminate the need for worrying about wiring in audio, and leave open a few other dock choices. The iPhone (3G/3GS) will route all audio over BT, and auto connect when you get in the car. Been using this myself for podcasts in the car lately. Mine integrates with the CarPC, but a friend of mine picked up some generic kit that hooked in via the CD aux in connector on the back of the stereo.