im guessing for an amp. there is a grommet just below and an inch or 2 towards the center from the battery(just look next to battery and you should see a black grommet bout the size of a half dollar) that leads into the passenger footwell. cut a hole in the grommet and run the wire through it, then however else you want to get it to the back (down center, drivers side?) i ran mine once it was in the interior along the firewall, then under the carpet along the door sill in some plastic square tube with some other stock wires, then under and to the side of my rear seat to the back.