hey mate
mine runs from the battery, alone the left side (looking from the front of the car), across the back to the right hand side side, and there is a little round grommet about 3-4 cm in diameter, its perfect as far as i know. i think you also need to take this into account b4 you run your wires, but i think you gotta make sure to run your amp AC (i think thats right), and your output form your head unit down different sides of the car, or it can result in your speakers whistling while your head unit is on.
hope this helps
yeh the same as MR VX jsut mentioned