Griffin Technology iTrip Auto is an FM transmitter that allows you to play your iPod through your car's FM radio. It features SmartScan technology for easy frequency finding, presets for saving your favorite frequencies, and LX/DX mode for switching between stereo and mono sound. The iTrip Auto also charges your iPod while it's in use and has a power switch to turn off power to the device and your iPod when your car is turned off.