I have a 2004 Suburban z71. I am wanting to leave the factory stereo intact and install a dvd player below it in order to supply 2 headrest monitors. I need to know what the best and easiest way to get a power supply that is run off the ignition for the head unit and the monitors. The truck also has a seperate rear stereo for the backseat passengers in the center console. I don't know if it is acceptable to tap into power there or not. A wiring diagram and some advice would be extremely helpful.