BIG important thingy is to use foam board or something behind it. Didn't use it first, and well, yeah, a whole lot of rattle. The foam board worked just as well as dynamat and only cost me two bucks too. Now there's no rattle and its sounds great. I'm not trying to blow the neighbors windows off, just adding some good punch to my rock music. Kinda nifty that it naturally fits right there and there's about half an inch of clearance to the floor when the gates closed and its snugged up to the plastic bar. Only modification to the plastic wire cover was using a dremel to notch out the end for the wires to the sub. I really wanted the whole thing to be as clean as possible, not take up a lot of tailgate room, and add a clear bass punch to my music. Did all 3.