I was pleasantly surprised to find how well the iPhone app worked in my car yesterday afternoon. I plugged it into my FM transmitter, started streaming audio (over EDGE, no less), and got pretty good audio played through my car speakers on my commute home. Didn't expect it to work with the car speakers through the dock connecter (some apps do, some don't), and definitely didn't expect such a steady signal while driving. Already worth the money I spent on it.