I would use the remote wire from the HU. I wired my RCAs along the door line on the opposite side of the amp power cable. If you wire it along each other you may get interference.
2000 Contour Zetec ATX Hector Mods...I got em' "Contour grills, Contour bills, check out the oil my Contour spills." 2.SLO = 17.6 at 80mph My profile
