It appears that using USB input with a different music player like Player Pro or Poweramp reequires the USB storage to be connected to the USB 1 input. It also appears that the DVR dash cam also needs to be in USB 1. The stock media player is by far the worst I've ever seen, and does not have a Folder navigation mode, only Song, Album, or Search option. Using a 3rd party music player app is fine, but is useless if it can't read the USB drive because I have the DVR plugged into USB 1. Can this be fixed with a firmware update? USB 2 and 3 are rendered useless by this arrangement - please make all 3 USB inputs have equal capabilities. My music library is far too big to fit in the internal storage.