Ya dont really wanna be running speaker cables along the same place as all the power wires. Im just in the process of upgrading mine ice, JBL power 6" component set, 10" infinity sub and highphoncics 4 chanel amp. As my battery is in the boot its easy to power the amp, the RCAs are run staright down the middle of the car into the boot where the amp is. The wires for the comps go back up the middle of the car and seperate at the front and off into the doors, in to the xover and then the comps. Its not really hard, just ver time consuming and a lot of effort to take a load of your interior out. You would be gutted if you spent time doing it only to get interference from other wires or crap wires.