Share your experience!
I have my phone connected to my car's bluetooth for audio playback. When I turn the car off, the radio stops, obviously, and my phone seems to pause whatever audio I had playing. But my phone immediately starts making very brief, periodic sounds. If I were to guess, it's trying to continue playing the music, but the sounds are so brief it's hard to say certainly that it's continuing the music. The sounds are perhaps 1/16th of a second, interspersed by perhaps a second of silence. It sounds sort of like:
KSH...................... KSH...................... KSH...................... KSH...................... KSH......................
It stops when I go into Pandora and click the "play" button a few times. I haven't done any further debugging or attempts to re-create the issue with other apps. I will update as I find any additional, useful details.