Taken from : http://www.macnn.com/reviews/griffin-itrip-auto-smartscan-fm-transmitter.html
Griffin iTrip Auto SmartScan FM Transmitter
October 1st, 2008FM transmitter with SmartScan to find the best stations.
Griffin Technology offers a number of different FM transmitter solutions for the iPod product line. We reviewed the more expensive RoadTrip with SmartScan and iTrip AutoPilot previously, but found them lacking in transmission. It seems the slightly less expensive iTrip Auto SmartScan fared much better in tests over different parts of the country.
I used the Griffin Technology iTrip Auto SmartScan over the course of a weekend road trip. I drove from North Carolina through Virginia and West Virginia up to Ohio. For most of the trip it worked very well. Ilene tested it when she drove through Boston up to New Hampshire a few times with the same result.
The iTrip Auto SmartScan has a few different ways of communicating with the user. The 12V auto accessory lighter plug has a ring on its end that lights up red to indicate charging or green to indicate that the iPod is charged.
The middle of the device is the rectangular channel selector with three buttons and a LCD screen behind a translucent silver face. From the moment the device starts up, it looks and behaves as if Apple had designed the interface, which is a compliment. Griffin uses an easy to see rounded rectangle progress bar for scanning stations on all its iTrip models. Your iPod is not secured by any attachments, other than the docking cord, which is similar to the iTrip AutoPilot.
The iTrip Auto SmartScan functions by searching for white space, that is the FM space where no stations reside, and then offers the three first spaces as preset options, selectable with the three buttons. Once you select a frequency number, such as 89.7 for example, you tune your FM radio in the car to the same station and the iPod audio plays through the speakers. The audio output on my iTrip was set to mono by default, but changing the setting to stereo is easy.
It's possible to use the device with a manually set frequency, but the advantage of this iTrip is its ability to scan for stations automatically with Griffinís SmartScan technology. The station-scanning feature worked similarly to the other models we tested, mentioned previously. Ilene had better success with the manual tuning in the crowded Boston FM market.
I used the iTrip in a car with a Kenwood radio on the trip up to Ohio, and on the return trip I drove a rental car, a Ford Focus with the standard FM radio. The rental car had the auxiliary line input, so if had a cable I could have used that instead of the FM input. In both cars, the biggest problem is larger cities where the radio dial is saturated and there are no available stations. I had no trouble while driving the back roads of Virginia through the Appalachian Mountains, but in Durham NC I found that the presets offered by the SmartScan feature didn't work well. After a few minutes of listening, a commercial station came through and I lost the iPod sound.
Ilene had better luck in and around Boston, and found that this iTrip Auto was able to broadcast over a weak station, but there was some static. She also didnít lose the station, as she did with the other models tested. This sort of problem occurs with any FM transmitter intended for use with an MP3 player and not just the iTrip.
The iTrip Auto SmartScan has an excellent interface and is very well designed in every respect. Even though it is not optimized for iPhone use, it worked fine with the original iPhone, but doesnít seem to work with the iPhone 3G. We tested it with one of each model phone, an iPod video, and an iPod nano 3g.
The only concern I have is the price, especially in light of how FM transmitters perform in larger cities. Is an FM transmitter, even an easy to use one that overcomes most interface issues of other FM transmitters, worth $80.00 dollars? Griffin Technologyís other models are even more expensive, yet didnít seem to work as well. The convenience of not having a custom car stereo installation and the SmartScan feature may be worth every penny spent on this model.
Excellent interface. Charges iPod while engaged. Easy to use while driving, but not recommended for safety. Cons
Expensive. SmartScan only mildly helpful in crowded FM markets.