It looks like a sub encloure behind the panel. It is a black "case" that takes up the entire inside of the rear passenger side panel. It must have some fans in it, can hear them runnig when I turn on the blower. Thre is also some metal hoses runing behind thre that get pretty hot, so there must be a heater core in there also. I id not see a factory amp, but have not pulled the panel to look. I think I am going to tackle the amp install. Just need to figure out how to get the dash apart and pull the head unit. Does anybody have the wiring schematic that would tell me what wires I need to tap into for the speaker line level converters, and th remote turn on for the amp? I just can't bring myself to pay over $100 for the labor...