Product purpose: The NewerTechnology RoadTrip!+ is an FM transmitter and car charger for dockable iPods.

Positives: Use of mostly empty 87.9 FM frequency alleviates the need for screen, buttons, presets or any interface. No setup involved. Inexpensive for a combination charger and transmitter.

Concerns: If something else is being broadcast on 87.9, product may become useless. Unusable if your car stereo can't be tuned to 87.9.

Pricing and availability: currently available from OWC for $25.99.

Company website: NewerTech.com

Works with: any dockable iPod (a similar non-tested product called "RoadTrip!" with no plus sign can be used with non-dockable iPods)

In detail:

Ask most users of FM transmitters which frequency they generally have the best results with, and the majority with respond with the same answer: 87.9 FM. Although it's located one notch beneath the lowest commercially broadcasting frequency in the United States, most car stereos can be tuned to it anyway, creating a potentially ideal choice for users looking for an empty frequency to send their iPod's music to. While some FM transmitter manufacturers have chosen to include 87.9 as a tunable option on their product and others haven't, NewerTechnology gets right to the point by making it the only frequency its RoadTrip!+ uses.

The results of this decision are surprisingly simple. The product's marriage to 87.9 eliminates the need for a screen, tuning buttons, preset buttons, or in fact any interface at all. The RoadTrip!+ looks no more complicated than a simple car charger, and its lack of ceremony allows its price to clock in at about 28 dollars, significantly less expensive than most combination charger/transmitter products. Setup is simple as well: just set your car stereo to 87.9 and then plug it in.

Although 87.9 is officially supposed to be empty all across the U.S., we were curious as to just how true this would turn out to be, so we took the RoadTrip!+ on an extended (ahem) road trip. For most of the trip, we were able to achieve excellent, uninterrupted sound quality. But at one point during the trip our sound quality dropped off noticeably. Sure enough, we unplugged the RoadTrip!+ to find that something else was indeed broadcasting quite clearly on 87.9. Some type of pirate radio station? We never were quite able to figure that out. And it was gone by the time we passed through that same area a few days later. But nonetheless it allowed us to discover the product's one weakness: if 87.9 is already in use, the RoadTrip!+ becomes more or less unusable until you've driven out of range of whatever is broadcasting. On the other hand, we were pleased to discover that even when a radio station is broadcasting strongly on the neighboring 88.1 frequency, the RoadTrip!+ seems unaffected.

Before buying the product, you need to determine two things: check to make sure that your car stereo can be tuned to 87.9 (most can). And if you can stand the silence, go ahead and drive your regular route while tuned to 87.9 to make sure there are no interfering broadcasts that will cause you problems on a regular basis. This still won't protect you from the possibility of running into a random pocket of interference when driving routes you don't usually take. On the other hand, no FM transmitter is perfect. We'd like to have seen the inclusion of a "bailout" toggle switch which kicks the product to some other oddball frequency in the event that 87.9 becomes unusable. But when you consider that most users will never have an issue, the overall simplicity of the product, and the fact that it costs less than half the price of most combination charger/transmitter products, the RoadTrip!+ shapes up to be a surprisingly strong option.

Learn more: NewerTech.com