Mediaplayer is playing over FM.
Incoming call comes in, mediaplayer paused. Seems like fm transmitter is deactivated and activated for call.
Call ends, mediaplayer resumes, FM-transmitter stays on and mediaplayer voice is routed to int. speakers, not over FM.
After ~30sec FM-transmitter stops and started again (by mediaplayer?) and mediaplayer's sound comes from car audio again.
This doesn't matter if i start fm-carkit under normal user or root.
Under user i get error "alsactl: save_state:1530: Cannot open /var/lib/alsa/asound.state for writing: permission denied" but didn't notice any differences in transmit behavior.