oh yeah, ground the amp as CLOSE AS POSSIBLE to the amp. I found the best spot is on the seat belt bolt (most common place) or just sand the primer off a metal spot in the trunk and get a short (1") screw metal in there *(use a star washer with the ground wire if screwing into sheet metal). ground it close to the strut tower, there's nothing electrical or mecahnical under there so its safe to drill and screw into (unlike the gas tank under the back seat...eek!). Just make sure the ground wire is no longer than a foot long (ideally) and preferably larger guage than the power wire.
