This is a very old topic. I Recently bought a used D3 and installed it in my Jeep. Instead of the old 12v is 12v system like in older cars, I had the canbus system found in most cars today. that required a integration harness. I ran into problems when the "drivers" door was not closed last...weird. If is wasn't exact, you would get in the car, fire her up and No sound... Sometimes I had to pull over, shut the car off, open the door close it, and fire up the jeep again....voila, sound. I ended up changing the Metra harness with another from Axxcess and I've never had the problem again.