I have a factoy system in the green 3kgt I picked up almost a month ago. Its a nice little system, with the 6 disc changer in back, aux input port on the face of the head unit to play music off of my phone. And where Im from, its less likely that someone will attempt to steal an oem head unit. My thing is, I really wanna hook up at least one 12" sub, Ive had a pair of 12s in the camry and a pair of 10s w/ a pair of 8s in my eclipse for a while. Ive seen the wiring harness that connects the oem amp to an aftermarket head unit, but again I want to keep the stock in there. Does anyone have any ideas?