If you already have an adaptor that will allow you to play your mp3 unit through the car's cassette player, use it. I expected this to equal that, and it doesn't, not remotely. And by the time you add the power adaptor, you looking at about as many wires as you had before. I found the sound quality to be poor, and unless I moved the wires JUST RIGHT, I could not get the radio to pick up the stereo signal.

I bought this product after ripping all my CDs to MP3 so I could use my PC as a jukebox and listen to it in other rooms. At a fraction of the cost of WiFi media solutions, it certainly does the job. It's obviously limited to radio sound quality but pretty much matches the quality of local stations as long as there's good reception.

I do wish the signal could be a little stronger, but of course it's legally limited. Mounted on the wall with an audio extension cord split from my front computer speakers and plugged into a universal AC adapter, it reaches the rooms adjacent to my office containing my PC, but needs a pretty hefty antenna to pick it up clearly two rooms away. Can't complain much about that since it's designed and advertised for use in a car. The signal itself gets stronger as the volume of its source increases, but there's a fixed limit at which the signal starts getting clipped, severely reducing the sound quality.

The availability of the full spectrum of FM is nice since I do live in a larger town of 250,000 with several radio stations. I found the preset function useful for storing several dead spots on the band to quickly switch if there's any interference.

I did use the unit briefly in a borrowed car while mine was in the shop. It performed fairly well, but it occasionally faded out in certain areas, and I definitely would prefer a tape adapter. It does the job adequately if there's no tape deck available, but I feel that it truly shines when in a stationary setup as in my house.

I bought this so I would be able to listen to my Creative Zen Touch in the car.

Pros:
-Full FM spectrum
-Adapter for Car
-Auto power on/off
-4 channel presets
-It works

Cons:
-The adapter cable is long compared to the cable that connects to the headphone jack.
-Depending on how the device is positioned, you can get a good signal or a bad signal.

I must say, the pros outweigh the cons on this device. As far as I'm concerned, as long as the music plays out of my car's speakers without static, then it is good.

Bought this to replace a similar item (iRock) that did not have auto-power-off, thinking my batteries would last longer since I no longer would run them down forgetting to shut the stupid thing off. Well the auto off works great but I am going through batteries MUCH faster than I did with the old unit. Other than this the unit works fine, but I am going back to the iRock.

I bought this of Amazon because the price was good and I needed an FM transmitter for my MP3 player and DiscMan. The first one I received just would not auto turn-on. It would turn on when I manually turned it on, and even the sound quality was acceptable. But then it would turn-off ever 60secs or so. I believe the problem was that it could not recognize the signal coming to it.

So I exchanged this for another and that one works beautifully. It turns on Auto, turn-off Auto. I don't have to worry. Also the car adapter comes handy as it saves the battery power. The good thing is, there is hardly any distortion in signal between the switch from battery to car adapter.

Pro's: Good quality, auto-on and off, well priced, not very bulky.
Con's: The first piece didn't work (had to replace it), the cable is too short and makes the unit hang with the mp3 player.

I would say its a good buy under $40. At the low price it would be difficult to find something better.