I have an idea to solve this iTunes music sync problem that have yet to be tested out since my F13 has not arrived yet (and my E92 is too old to support it). If you could somehow get an Airport Extreme or Express within the range of the car, technically you can remotely sync the iPhone in your car without ever removing it. New music and playlists on your iMac can wirelessly sync to your iPhone. Effortless new music selections as soon as they are purchased. Will it work or am I dreaming?
Still would not solve the overheating problem. Perhaps an iPod Touch may do the trick. Not sure.