I just received my Jensen Power 5500 amplifier. This thing is huge. Roughly 21 by 9 inches. My plan is to put it in the trunk, but in such a way that it doesn't get fried by water dripping from a wet ski that's protruding from passenger compartment or by water spilled from a water jug, or rain water dripping from above when the trunk is open. I also hope it doesn't get crushed by anything I might put in the trunk. Given these concerns, what's the best way to mount this amplifier? I am thinking that it would be neat to put it on the left or right wheel wall, but how do I attach it there? It comes with four holes at the edge for mounting it.