i just got a subwoofer in the trunk, but it slides around / moves alot. i bought 4 L-beams like 2 inches big and was wondering if it is SAFE to drill inch-long screws into the bottom of my trunk. the ground wire for the amp is drilled straight into the bottom of the trunk so i guess thats fine but is there anything to be concerned about before i drill holes? gas tanks or anything electrical lol. thanks.