I took the seat completly out back and all. Made a brace out of some scrap I had, bolted this into the floor. Use 1/8" plate to make the floor. It is bolted to the brace and where the seat back bolted into. I did this so I can put the seat back in if needed ( 3 kids). Had a tool box & hi lift bolted to it for the Moab trip. If I am going to sleep in the back I put the jack underneath. I don't have any openings in the top, but the sides are open. If anyone wants pics. send me your email & I will send some. Jim