Because of the odd shape and articulation of my bed floor, I've gone thru a few variants of wheel tub design to accommodate it. The first one I did way back was too thin and looked flimsy upon install.
This time I went with a matching-gauge aluminum and tried a more angular polygonal approach. It leaves the bed more usable and gives a little more protection. I've got a few attachment ideas, but I may not even stick with this design as things move forward. I've become so used to no wheel covers that the look has grown on me.