This is a link to a YOUTUBE video of a quick build I did for a platform to sleep on inside my F350. I just painted my canopy (came with another F250 I bought), and mounted this inside. Built it on 2x12 runners to clear my 5th wheel bedrails, to give room for storage underneath, and to lift the platform above the wheelwells, so our double mattress would fit. Turned out great, if I must say so myself! Easy to remove and put in my other truck, if necessary.
My wife and I are headed to Moab for a couple of days, and we figured most nights we'd hotel it, but 2 nights of our trip we'd spend in the back of this truck...... should be fun!
Haven't used it yet, but will before the week is up.