I checked this out early this year with the 665. Could not find any method to output audio from the 665 through Bluetooth - this Zumo doesn't support mp3 bluetooth out, while the 595 does. I installed a Lanzar crossover preamp with Bluetooth to receive Bluetooth from my Iphone, and picked up a Ball-style mount for the phone (thanks for the lead, Seth). Send tunes from the phone via the crossover/Bluetooth preamp, through the amp and use it to listen to Pandora (or whatever tune source you have on the phone). I've found that I can usually get Pandora via the phone except when really in the boonies - like in mountain valleys. Around towns and anywhere near interstates, no problem. I also listen to XM/Sirius and MP3's via the 665 - they increased the mp3 count supported to 2000, from the limit of 1000 on the 550. With a couple SD cards loaded (one in my pocket) I am never at a shortage for music, with MP3's, satellite radio, and Pandora or whatever on the phone, as options.
IIRC, this crossover is available at Amazon under $50. The first one had a glitch but they replaced it immediately. Note it supports 4 channels plus subwoofer if you have the toys.
If you want to set up something similar, note the Lanzar has the Zumo as Front Input. When you connect Bluetooth, it gets priority and input from the Zumo is disabled. If you shut off the Lanzar, the Bluetooth connection is dropped, and then you can make the Zumo output active. So set it up so you can switch the lanzar off. To activate Bluetooth (and Pandora) turn off the Zumo output. Assuming you have set it up to automatically connect, the Phone will connect and you can turn on Pandora. To switch to the Zumo (mp3's or satellite) switch off the Lanzar, bluetooth is dropped, turn on the Zumo tunes, and switch the Lanzar back on. Easy-peasy. I set mine up with a 3-pos sw for the amps, Up is on with the key, mid - off, down on. Of course for the latter, that's for playing music on a club ride at the motel while we are sitting around telling lies and drinking Markaritas. With a charger maintaining Jade's battery.
BTW, I have the audio output from the 665 coming out of the plug on the loom, not plugged directly into the Zumo. The 665 is the same as the 660 except it is packaged with the XM antenna. Which you can purchase separately if you decide to add satellite connectivity. Don't know if there is an audio out plug on the 660 loom. If your sound cuts out - they have a problem with the connector pins on the face of the Zumo mount. They are spring loaded and sometimes don't pop out properly. Clean them with contact cleaner and ensure one or more aren't retracted. If the music cuts out while riding sometimes you can pop the Zumo off and back on and remake the connection (at a stoplight). Garmin's tech support didn't know this I had to tell them. AFTER they replaced one of my mounts with stuck contact pins.
