I just bought Griffin iPod Touch FM Transmitter and Auto Charger via Amazon for $15 that is with FREE shipping!! Original cost was $69 so that's 77% off the price and I thought sharing with you might bring some happy car trips to you as well.
I do not know how long this FM Transmitter deal is going to last so my suggestion is if you have $15 buy it today. If you are looking for iPod FM Transmitter or Charger than go to Griffin iTrip.