We purchased this unit about 2 months ago. It is my second FM transmitter - my prior one was an off brand product. Initially, I was somewhat disappointed with the Belkin. Any level of external transmission on a station causes distortion - this is a problem when driving through a city as channels drop in and out. The saving grace of this product is 1) you can tune in almost any FM station and 2) the easy controls for changing stations. If one finds the right channel (keep trying!), the product works well, but it does take a lot of trying. If you are in a city, you may have to change the channel several times as you drive.I have always powered it off car power as opposed to using the batteries.I haven't had a problem with the unit automatically turning off. We use this only with our portable DVD player. When it is working well, the sound is good though it may not be stereo.