I am using my Nexus 7 in my car for streaming music via bluetooth to my Alpine head unit. This works just fine with Google Play Music, but I dont like the interface. I have 2 other music players installed - Poweramp and Zimly - which I much prefer to use, only problem is if there is no music playing on either of these players when I switch to blutooth audio on my head unit, I get no sound and "Bluetooth Audio paused" displaying on the Alpine unit. Same thing happens if I have a song playing when I select bluetooth audio - music will play fine and the head unit picks it up no problem, but if I pause it for more than 3 seconds I just get the same message "Bluetooth Audio paused" and it will play no more until I actuall scroll through the inputs to bluetooth audio again. I initially thought it was a problem with the stereo, but Google Play music works fine with absolutely no problems, and my Galaxy S3 also works fine. It's as if Google Play Music is blocking any other apps from fully functioning?