Check out the line of 5th wheel tool boxes shown on AMAZON. Type in google search "5th wheel tool boxes for truck AMAZON" lots of photos...
I also have the Fold-A-Cover four folding panels mounted on my truck and when I used my fifth wheel I could fold them back up behind the rear window and all cleared just fine...
I notice some of the trucks have a low profile storage box across the rear of the truck bed that is notched out to clear the 5th wheel.
I never liked the idea of not having a locked tail gate and bed cover when unhitched...
Roy Ken