Summery: Tried Griffin iTrip Auto Universal Plus FM Transmitter in my car, it provided significantly better results listening to an MP3 player in the car over the Belkin Tunecast II I tried a few years ago but if I had the option I would still prefer to use a cassette adapter.

A few years ago I wrote about how to connect and iPod to a car’s stereo. There are three ways to connect an iPod or any MP3 player to your car, use a line-in jack, cassette adapter or an FM transmitter. Fewer cars today are sold with a cassette player and surprisingly few cars come with line-in jacks or iPod dock connectors leaving many people are left with only option and that is to use an FM transmitter.

Last year I bought a new car and I became one of those people whose only option was use an FM transmitter if I was going to use a MP3 player in my car. Due to the terrible experience I had with the Belkin Tunecast II a few years ago, during the first year of owning the car I tried to get by without an MP3 player however between very poor radio station options and getting tired of shuffling between CDs while driving, I decided it was time to try using an FM transmitter again.

For my second attempt, I selected the Griffin iTrip Auto Universal Plus FM Transmitter (Model 7259-TRIPU). I selected this transmitter for four reasons.

1. This model of the iTrip will work with almost all MP3 players. Some people have reporting having problems using their iPhone while others have had success. Griffin does make an iTrip FM transmitter that looks and functions almost exactly like the one in the picture shown on this page except it comes with a dock connector.

2. Second the transmitter draws its power from your car instead of using a battery or the MP3 player itself. Even with the MP3 player and the FM transmitter together they will not use very much power so if you do forget to turn off the player it will not drain your car’s battery overnight.

3. The iTrip will keep your MP3 player charged through the player’s USB port, provided your player has one. Some MP3 players will not charge through USB such as the first, second and third generation iPod and the second generation iPod shuffle.

4. The transmitter will turn its self off one minute after you pause or turn off your MP3 player. Some people have reported problems with the transmitter turning off while the MP3 player is still going. I also had this problem at first but after I turned the volume of the MP3 player to the highest volume setting the problem when away. To my ears setting the MP3 player volume to the maximum setting and using the car’s radio to adjust the volume, the sound quality was better than using the MP3 player to adjust the volume.

5. The last reason is the player will allow you to set the transmitter to international mode* giving you access to transmit on the 87.5, 87.7 and 87.9 FM frequencies (some car radios are not able to go below 88.1 while others such my car will only go down to 87.7). Only a couple stations in the US use frequencies below 88.1 so if your car radio goes down that low on the dial you are almost guaranteed to have an open frequency to use.

I have been using the iTrip for almost two weeks now for almost an hour a day to and from work and I have found that it works far better than I had hoped, however after using the Tunecast transmitter a few years ago I had very low expectation. The sound quality is about as good as you would expect, it is on the level of a commercial radio station but not as good as a CD or using an cassette adapter.

Occasionally I do get static a few seconds while going under bridges or passing a car using the same frequency as me but the static does not last long enough or happen often enough to bother me, over the course of an hour I may get static for a total of three or four seconds. I am willing to deal with a little static every once in while if it means I will not have to listen to the local radio stations.

Using an FM transmitter should still be your last option to listen to an MP3 player in car because how well the transmitters will work varies greatly from car to car but if you have no other option it is something worth trying.

* To set the iTrip to international mode hold down the preset button for about 30 seconds. US will start to blink in the upper left hand corner, keep holding the preset button down for about 2 two more second until INTL starts to flash, when it does let go and your iTrip will now let you use the lower FM frequencies.