i just put a new modern stereo in my TA and camaro and both have usb playback. i like the usability of the usb stick but a lot of the songs on my i tunes that i transferred to the usb stick will not play on either on my stereos. seems like the ones bought off i tunes and the ones i got off my cd's that are both in my i tunes library will not play in the car which is most of my songs. this is ridiculous, i think they are mpeg 4 files, the mpeg 3 files play just fine. can i convert the 4's to 3's or do something to get them to play in the car, they play fine on my ipod and in i tunes library. thanks for any and all help.