Thanks Red GTi, this all looks very helpful (except the last link goes to a blank page...)

As far as amperes and wire gauge, I'm not sure how to convert amplifier watt output to amperes drawn. I have two four gauge wires running from the battery, one to each amp (1500 watt class D sub and 400 watt 4 channel) with two four gauge wires going to ground from the battery (ground wires from the amp are also 4 gauge). How wold I convert that into amperes?

Also, I just bout an Interstate Red Top battery which I will put in with the same setup tomorrow (replacing honda stock battery). The only other thing I can think of is to change power wires from alternator to be 4 gauge as well...

As for the install, wires are all clean, all power on one side of the car and all RCA on the other. I hope there's a difference tomorrow...