Pros: A strong FM transmitter and auto charger in a single car accessory, with relatively low static levels and strong audio quality on our standard test channels. Provides wireless broadcasting to U.S. and international radio stations, your choice between higher-quality monaural or lower-quality stereo broadcasting, and does not require iPod or other battery power. Slick black enclosure and nice LCD screen are easy on the eyes.
Cons: No preset functionality, and channel tuning box is located in the middle of the cable rather than more conveniently at its car charger end. Stereo mode performance isn’t as strong as top competing option, price is on high side of overall range.

Over the last six months, we’ve seen more iTrip-related announcements than in the preceding three years: Griffin has shown or released a new top-connecting iTrip with LCD, a bottom-connecting version, a totally different nano-specific model, and now this – iTrip Auto ($70) – a car-specific model. All four devices have the same core feature – an FM transmitter that wirelessly broadcasts your iPod’s music to a stereo system – but they differ a bit in the specifics.
iTrip Auto is a direct competitor for Kensington’s Digital FM Transmitter and Auto Charger (iLounge rating: A-) and Belkin’s TuneCast Auto (iLounge rating: C+), which previously bundled LCD screen-aided FM radio broadcasting and iPod charging functionality into single accessories. Griffin’s option lets you plug a black bulb into your car’s cigarette lighter/charger, then a slim black Dock Connector into your iPod’s bottom port, and then tune FM radio stations with a brightly lit LCD screen and three controls. Because it relies on your car rather than your iPod for power, iTrip Auto can be used even with an iPod that is fully battery depleted, and properly recharges iPods that are attached.
Though iTrip Auto shares the same general features as the two LCD screen-equipped portable iTrips, its buttons have been moved around. There’s now a flat circular station up or down button, then a smaller circle labelled “Select” immediately besides it.
You pick a station with the up and down buttons, then hit Select to confirm the choice. As with the company’s LCD iTrips, holding down the Select button lets you toggle between U.S. and International radio stations, as well as LX (stereo) and DX (monaural) modes, the specifics of which you can read about in our prior reviews. You’ll get less static interference on DX mode, but your music’s stereo separation will be eliminated in the process. U.S. tuning now allows you to reach our preferred “clear” station, 87.9FM, without having to choose International mode.
While we liked the mostly glossy black design of iTrip Auto, Griffin’s physical design is functionally someplace in-between Kensington’s and Belkin’s. We didn’t like the awkward cable dangling and mounting needs of Belkin’s option, so thankfully Griffin hasn’t gone entirely down that road with iTrip Auto: the FM transmitter box is in the middle of the cable, and its location does not appear to significantly impact its broadcasting performance. But Kensington’s choice to mount its LCD screen and tuning buttons on the car charging bulb proved the best of all these options, making tuning a comparative snap – except for one factor – and providing the easiest way for a user to know visually when the unit is powered on.
The one way in which Kensington’s option suffers by comparison with iTrip Auto has to do with that 87.9FM station, which we focus on as a nearly ideal choice for FM transmitters because it’s almost guaranteed to be empty no matter where you live in the United States. With iTrip Auto, you can tune 87.9FM, turn off your car (or unplug iTrip), turn it back on again, and resume use of the channel immediately.
Kensington’s Transmitter can only tune 87.9FM through an odd button combination, and loses the station every time you turn your car on or off – something that doesn’t happen with stations from 88.1FM to 107.9FM, especially given Kensington’s three preset stations. Belkin’s TuneCast Auto can’t tune 87.9FM at all, but it also has two preset buttons. Griffin makes 87.9FM the easiest to tune and save, but has zero preset buttons.
What does all of this really mean? If you’re in an area where 87.9FM works reliably, and you won’t need to toggle between stations, iTrip Auto will be your most convenient option. If not, Kensington’s multiple presets and more convenient tuner are probably a better match for your needs, as iTrip Auto will require you to manually tune each additional station you want to try.
On audio quality, Griffin and Kensington’s products are nearly an equal match. We’d give a slight edge to Kensington overall for one reason – iTrip Auto does best when it’s in monaural (DX) mode, providing a low level of static that’s comparable to Kensington’s product, as well as strong, dynamic music that’s generally very pleasant to listen to. But Kensington doesn’t need to switch out of stereo mode to achieve comparable performance, and iTrip Auto’s static level isn’t as low when it’s broadcasting in stereo. This mightn’t – and probably won’t – matter to many users, who either don’t realize or care that their music has separate left and right sounds, but for everyone else, it can’t be totally overlooked.
iTrip Auto fared very well in our standard in-car audio tests. It tuned 87.9FM cleanly, with a low level of static and relatively powerful audio that – other than stereo separation – was comparable in overall quality to Kensington’s product. Kensington had a slight edge on treble response, Griffin on bass.