i could be wrong...but my understanding of the usb capabilities of most head units was that it was for things such as usb thumb drives...ie: nothing that requires it's own set of drivers.

Unless it specifically says that mp3 player works with that head unit in the manual.

As far as I know though, the creative line of mp3 players do not stream music over the usb, it's only for data transfer.

1999 Silver Frost SVT #609 of 2760 Quaife, lightened SVT Flywheel, SPEC stage II clutch, removed resonator, k&n drop in - various other goodies too.