I just got a new amp from my parents as a late birthday gift. It's bigger than the one I have, which is mounted in the cargo box next to the battery. I don't know where to put it. I would attach it to the sub box, but it will also be powering two speakers in the factory locations. I was thinking of getting the rear cargo cover and door thing (I don't have any now) and attaching it to the door, as I've seen done before. Is this a secure place to mount it? Also, how do you attach it to the thin material, and will it damage it at all (aside from screws or whatever)?