just a warning, watch where you buy your amp kit. Ive been ripped off twice with undersized wire. Bought a kit at a big name electronics store in town, they were selling it as an "alpine" kit but really all it says on it is type x. Its in the same colours and font that alpine uses so everyone assumes its alpine, even the store. Second kit i bought was on ebay, absolute worst thing ive ever bought online. The 8 gauge kit he sold me came with 14 gauge wire... 4x too small.
Anyways, i ran my rcas and amp turn on down the drivers side with all the other cable. Its was a major pain, i wound up taking the seat out to get the cables in. Going to do the power down the drivers side, i would just drill a new hole in the firewall for the cable, and dont forget to use a grommet