I looked through all these threads and didn't really find anything that might address this. I have an iPod plugged in via USB. I can start the car and select 'usb' from the interface and the music plays from the iPod. Randomly, sometimes after quite a while, sometimes after only a few songs, the system will stop playing music, a box pops up on the screen saying something about 'navigation SD card fault' and then immediately switches to the last input I used, usually AM radio. Car is a '14, bought in July of last year. Haven't done any updates to the system. Should I try that first? Sorry if this has been discussed before, I couldn't find it.