You should do what I did, I installed a bluetoothe receiver for music while my car day Bluetooth but it only worked with phone calls. However adding a Bluetooth reviver and plugging it into the aux I can now stream Pandora. Take a look here to see what I bought:
http://e89.zpost.com/forums/showthread.php?t=1177523
Now whe I get I go the car my phone automatically connects to both the cars Bluetooth for calls and go the receiver for streaming. It feels like a factory deal.
Questions? Let me know.