I have the non-touchscreen stereo. I use it in USB mode with my iPhone, and I use the iPhone for everything: music, navigation, etc. So it is infuriating how frequently the stereo just flat-out fails to work in USB mode. Sometimes it can't finish indexing the songs, other times that's no problem. But often it simply won't play any sound at all while in USB mode: no music, no apps, nothing from the phone at all. Sometimes it starts working after a minute; usually it doesn't. I tell it "Play" and it tells me that command is not available. I try various combinations of cycling the source, power cycling the car/phone/stereo, cycling the iphone from Sync to Dock Connector mode etc., and eventually it works -- but i have no idea why. Good thing I'm not trying to impress anyone by showing off the infotainment system. Any idea why this happens? What can I do? Maybe the system hangs due to too many songs or contacts or something?