I have charged my phone using the rear USBs and that works fine. I also have charged my phone on the charging pad; works fine. I cannot use the front USBs to charge my phone. That is why I suspected that the front USBs were data only. Upon reading the instructions that came with my SYNC 3.0 Map upgrade, it says to use one of the USBs, not specifically the front USBs. With the front USB, the thumb drive blinks blue for a second, then nothing. Just now I tried one of the rear USBs. The blue light came on and stayed on. However, there was no response from the SYNC screen. So the thumb drive appears to be operational, but it cannot reach the map software. To answer your question, I did not see any indication of a media source on the Audio screen after plugging in the thumb drive. That must be why the dealer said the Media Module is bad. Now I'm back to my original question about what is a Media Module? I suppose taking it to a local stereo shop may be more cost effective that working through the dealership.