If this helps. Michelle's cargo box (a soft box) was going bad, attachment points were tearing off so it needed replacement. I got this metal box from a friend cheap, so what I did was remove the plastic cover on the rack and drilled out 4 holes to slip 4 bolts through. Took some plate steel and drilled & tapped to act as thin nuts. So now the bolts act as studs. Drilled the holes in the box and used knobs to screw it down to the rack. This makes the box removable if needed. I used some thin gasket material around the rack to help dampen any noise it might make, but just from trying to shake it, this sucker is on there solid. I bought a cheap outdoor floor mat, cut to size and used it for the bottom of the box.