The factory head unit is mounted in the trunk with a wiring harness connecting it to the aftermarket deck, somehow under the carpet and door panels in the car, I think. I have no idea really where it's connected to but I'm assuming it's connected to the cd player. I'm just as confused as you are. But
this is the thread that I was directed to when I first bought the cd player back in May. Maybe that will help you understand it more. Myself, I have a monthly miagrane and I'm just ready to say f*** it. It just pisses me off that I paid $175.07 (can't forget the 7 cents) to have a cd player installed that I already paid $165 for and the sound quality isn't worth a poop. Let me try to explain the static noise. You know fuzzy sound you get from a tv when the station goes off the air? That's what I'm getting out of my speakers when I turn the car off. It's not constant. It goes off when I open the door but still, it shouldn't be doing it. Even
I know that.