Wanting to install amp with RCA's and wiring etc

[GrantDavenportPhotography]

Hi all
I'm slowly building the sound system up in my 2010 TK Barina / Aveo and want to know if anyone has suggestions of the best way to get my amp's wiring through the fire wall and out to the battery and also the easiest, best and quickest spot to run the rca cables along under the carpet ? ( drivers side - passenger side - down the centre maybe... )
Also too, the amp will crank harder into a 2 ohm load however I only want to run the one sub so is there anyway I can wire up the sub, maybe with a resistor wired into it, to have the amp see only a 2 ohm load as opposed to a 4 ohm load



I've got 6 and 3/4 inch 70w RMS splits in the front, rears to be replaced soon and a 12 inch sub in boot with an old school rockford fosgate USA made amplifier running it. Running off a Sony CDX-GT300MP head unit.
I'll include some photos of the various bits n pieces soon. I have loaded a video on youtube of the front splits installation.
This can be found by searching 'installing speakers into Holden Barina' - or click this link here

http://youtu.be/0u4NvCj1LYc

i'll add more to youtube as I go.

any suggestions would be greatly appreciated
cheers and all the best and keep up this freakin' awesome forum - it ROCKS !!!!!!