I recently installed a Kenwood doubled in screen in my 2007 4runner with the fac tory JBL system in it with factory amp and subwoofer. I was wondering how to get the factory amp and subwoofer to work with the aftermarket stereo, and how to connect the center JBL tweeter to the system since aftermarket stereos only support 4 speakers. I bought the correct harness and stuff just cant seem to figure those two things out.