I posted this thread awhile back.
Course nobody responded. But I have the JVC dual DIN unit. It works great. During the 2.2 update I had to wipe the phone and later clear out the Headunits memory for BT devices.
But after that it works great.. meanwhile BT streaming works as well, tunes or pandora. I don't use it but I tried it. next thing I keep meaning to try. USB cable with phone set to mass storage.
However it has 2 ports, and I have the rear port setup with a 16gb memory stick. Works great and reads fast and it stays in the glove box. You would never know it was there.