Originally Posted by Szadzik
Guys, it has nothing to do with Cingular or Tmo. It only depends on the quality of cables used in the car stereo. If they are of good quality, there will be no interference, but when the cables are crap there will be a lot of interference.
That's the problem.
That was going to be in my question. Is this an aftermarket car stereo or stock? If you put the system in yourself, you need to have a better ground as well as good quality rca jacks.