alrighty, i'm learning a lot,,, so I'll use the stock wiring in the doors, the back ones are easy to re-wire cause the amp will be right next to them and I will use heavier gauge wire to what is added for the fronts.
here's how the thing will work,
-Amp in trunk & use speaker level inputs on Amp.
- splice into speaker wires behind HU and use to relay speaker level signals into Amp, keep all ground wires spliced together.
- run + & - speaker wire from amp to rear speakers (really short run)
-run & splice heavy gauge wire from amp to front + & - speaker wires behind head unit.
pretty much like this