I'd love to figure this out too! I got a new car and my USB stereo can't detect my G1 phone and I'm really annoyed with this. Yeah having the name of an song and info coming up on my read out in my car is great but I rather have this work so I don't have wires all over the place and I can navigate my music from my the stereo interface instead of pulling out the phone and navigating while in traffic... It's reckless and I can get fined now in my state for messing with my phone like that b/c it's an action like "texting". Not only that but it really does require a lot of attention to mess with the phone to do something when it's easier to press 3 buttons on my car interface that is closer in relative distance to the road viewing area and my eyes are already focused on the road. (This may have not made sense... But when your eyes start to focus slower on close to far things like mine it makes sense.)
If there is anyway to maybe have the phone to tell the system the phone is like an iphone. I know the car can read thumb drives too. But it works only some thumb drives. I tried to have the mount sd card apps allow me to press it in the same time as pluging up the phone but it didn't work either.
