We have an FM transmitter in the car for Mrs. Chikken's Ipod, it's the one that plugs into the 12V outlet and doubles as a mount fer it
Works fairly well, will drown out some weaker signals so we don't have to change channels as much.
But the songs from older CD's (Like original U2's, and others from the 80's) are REALLY quiet and we have to turn the volume way the frell up to hear 'em, so those are more affected by the interference from other stations