That is almost exactly what I am looking for. I do not want an enclosed container because it would soon look like the back of my car, totally full of crap.
What are the dimensions of it?
The inside is 33x48-1/2. Outside is 37" deep x 52-1/2" wide. Sticks out from frame about 1-1/2" either side. But looks okay from the back cause the mud Buster's widen the rear fenders quite a bit. And the walls are 11" tall
I made a similar sized dump bed out of wood a couple years ago and I use it all the time for hauling tools and whatever. Only problem I've had is keeping the tailgate from vibrating by using a couple of carpenter's wedges.
Since mine is wood it runs much quieter when I leave the tailgate hanging down by the hinges over the muffler outlet.