What's the best way to play music from my iPhone in my car wirelessly? I have an iPhone 4 (and have pre-ordered a 4S] and I have a car.  I'd like to play the music from my phone over the car's speakers easily.  I know I can get a cord that has a cigarette lighter adapter on one end and a 3.5mm audio jack on the other but I'd prefer to do it completely wireless if possible.

Has anyone had any success doing this?  If so what device(s) did you use?
You need a Bluetooth stereo if you want NO wires or adapters, but it constantly cuts out (check other forums). You'd be better off with a direct connection, or an adapter/cable to send it over tr FM waves