My tennis teach has a in car setup consisting of a huge subwoofer, alphine headunit, and some speakers and tweeters. No matter how fast he drives or how loud the system gets, there is no noise that does not come from the disk playing. Its all about were you run the wires. Like the first link on google said, make a "sniffer" and don't run the wires over the place with the noise. Also its better to use a single shielded camble instead of 2 shielded cables.