Adding an amp with rear speaker inputs.
#2
You can get all speaker wires from the drivers kick panel. I'd highly recommend not using that style conector as water will get into that trough and you are going to introduce green rot into your speaker wires. Warranty will not cover that in any way, and as a heads up the wiring harness you are tapping into is one piece from the firewall to the 3rd brake light. Picture added to discourage this type of modification.
Really fun to replace
Really fun to replace