GOgroove SMARTmini BT ADVANCED Wireless In-Car Bluetooth FM Transmitter with Charging, Music Control and Hands-Free Calling for ANDROID, iPhone, Blackberry and Windows Smartphones
So far I'm satisfied.  Used on a 120 mile round trip and had no station overrides during the trip.  Works better than another one that I have that connects directly to the iPod.  The one that connects to the iPod depended a great deal on where the iPod was placed.