Should I completely bypass the factory installed Phone, Amp, CD Changer and Junction Box (splits supplied power to Amp and CD)? That would leave me with +B, ACC, and (combined GRND [plus the speaker/sub woofer] wires; which I would then just directly hook up to my new head unit. I wouldn't be using the wiring harness, and I would be have to cut a lot of the factory connectors.