here is what I did.
rounded the corners and edges
got some 2 in by 24 in foam padding from hobby lobby and used spray adhesive to glue it to the board
Then got a 4x4 from home depot with some rubber footings just in case so the wood legs wouldnt rub through the carpet after extended use
I then wrapped in in this dark brown burlap type material that i got from Hobby Lobby as well. I chose this fabric for the durability, my rotty has some big claws. I know that some of it is uneven, where I stretched it harder in some spots but im no pro anyways.
and here is my boy enjoying himself it puts him near level with the arm rest.and there is no slipping and sliding around. there are actually three support legs on the bed. it may be overkill but it works. the board is the same stuff speaker boxes are made of, it was the thickest Home Depot sold and lighter than any other material. also the bed fits snug against the seats and doors of the truck, so there is no chance of him being injured from a leg falling in a hole. The bed is also light enough so that I can easily maneuver it in and out of the truck.