I purchased an FM transmitter from Satechi and I find that it generally sounds like crap. Maybe it's because I'm in NYC, but the interference at times is unbearable. Even the "best" channel seems to have a hum to it. So now I'm looking to move to just a windshield mount so that I can connect it to my car's aux input. Amazon is generally a great source for iPhone accesssories, and they have a great app as well.