Read Griffin iTrip Auto (2010 version)
If you're like me, your car is a little too old to rock an auxiliary output connection for attaching your i or Zune. Generally the only alternative to installing a new deck is to either use a cassette adapter or settle for an FM Tuner adapter. While...
Overall the iTrip Auto is a very solid product, that being said it does have some quirks to it with regards to audio interference from other radio stations, and even in some cases other transmitters from cars driving by (ie XM-Radio transmitters.) But...
Review: Griffin iTrip Auto
Inobtrusive FM Transmitter for most iPods
Read Griffin iTrip Auto (2010 version)
Pros: Size ; Compatible with iPhone 4 and iOS 4 (with the exception of the on phone app) ; RDS
Cons: Weak Transmitter ; Interference was frequent ; SmartSound isn't working as advertised
Review: Griffin iTrip Auto
Pros: Includes a fuse. Large display. Inobtrusive. One piece. Works with 3rd generation iPod, plus newest ones
Cons: Loses reception sporadically. Priced too high