Dissonance
Member
If you aren't afraid of tearing into your dash, I'd recommend the T605. I have it installed in my VW GTI. By connecting to the correct phone terminals on the stereo the CD player will pause if a call comes in and all audio is routed through the stereo. If the stereo is off, phone calls still get routed through the speakers. It's one of the best items I've ever purchased for my car. I also use it to listen to Pandora all the time.
This is all you can see of the T605 in my car:
This is all you can see of the T605 in my car: