Your software instructions clearly lay out 5.1 procedures but the hardware/wiring directions only address 4.1 with a small note to addresss the 5th (center channel). Why not include the 5th channel wiring connection info in with the rest of the amp connection info - less confusing or missleading. Nice write-up BTW.
Is there actually enough power on the lines running directly from the MB to the amp? Don't some amps require a minimum voltage input? What sort of voltage are we possibly looking at that will be available to the amp once we've made the extensive run of RCA cables from the front of the car to the rear where the amp(s) is/are located?