dont take this the worng way but its not that hard. It seems your overthinking it.

- find a grommet that goes throught the firewall. Its usually on the passenger side for the ecu wires. Either yank it out from the engine side OR get a long screw driver and peirce it with the power wire attached.

- Rca's and power wires (remote wire included) should be on opposite sides of each other in the vehicle.

- remove kick panel, door sweep looking thing and run your wires in through there.

- Tuck your wires in really tight behind the rear panels and make sure to feed the wires behind any seatbelts,panels and other items that make move or stand out.

there you go!