Works well if you have channels with empty air - but will eat through your AAA batteries fast. I normally leave it plugged in to the lighter in my center console & just connect & disconnect the Ipod. The Lighter plug will also power your Ipod - but you need to get the Belkin one. Good tip + product - .
Belkin - FM Transmitter, Tunecast II for Apple iPod is recommended by Freddy1
Belkin transmitter transmits on FM channels 88.1MHz-107.9MHz. Memorize up to 4 FM frequencies. Powers on and off automatically. Features low-battery LED indicator. Includes DC cable for optional battery-free operation - Only works with the Belkin Mobile Power Cord for 3G iPod® (part # F8V7067-APL). Operating Range: 10-30 feet (a distance of 10 feet or less will minimize interference and provide the strongest signal).