+1 I don't and have never used any audio output from my GPS. I do use my Sena to answer and make voice-dialed calls through my Android phone and use my iPod Touch to play/listen to music.
Of course, it doesn't help that my Zumo 660 has a known problem with its Bluetooth implementation (besides crappy audio fidelity) that makes it problematic to really use it paired with my phone and the Sena paired to it.
FS: 2009 BMW R1200GS
, '05 GSX-R1000
Iron Butt # 4999, (former) WERA/CCS EX # 666, AMA Life Member, Drummer, Bassist