@StephenCasey,
So what you're saying is you want to connect your smartphone to your vehicle entertainment/control system via USB, and have it playback music stored on your smartphone?
My understanding is that the stereo needs to specifically support this, and none of the vehicle entertainment/control systems I've used over the years have worked this way with Android... Apple always does, but never Android.
It's frustrating I know, but I've tried to get this working myself and no matter what I do, it never seems to work... A bluetooth or auxiliary cable is going to be your best bet.
