I paired my phone with my Honda today. Fine for a while, then constantly connecting and disconnecting. When I got home, I tried to pair to two other BT devices. No luck. Looks like an exchange tomorrow.
My wife says she experienced similar issues with our Volvo yesterday. I ran Google music through BT in the same car from my own droid mini for around 3 hours combined today and had no issues, though..looks like I'll need to test her phone and see if I can reproduce it.
You may want to try clearing any connected BT devices too...and starting over with the car first. Then monitor that for a while and see if's stable before adding others.