I too have the 2- 5ft Rhino sections with caps, it stored nicely in the bumper and removed easily until our final outing last fall when some furry "friends" decided to pack some pine needles and acorns into the bumper as well. -needed extra effort to yank out the first one no problem, but needed to force the 2nd out with the hoe I always keep in the truck bed (garden variety folks, keep it G-rated)
Not wanting to deal with that again; I am currently using an empty Tidy Cat litter container with the built in lid.... works great and both fit snugly in there. Cost $0
Eventually I would like to do a similar PVC mod, but it's further down the honey-do list.