Nice video but everyone needs to find arrangements which work best for them. This would definitely not have worked well for us. My wife and I traveled fulltime with two cats, one was well over 20#. I would definitely not want the cat pan behind the front seat of the truck. When our big boy let go, the smell would gag an ox. We put the cat pan in the shower stall area and used a screen on the drain to prevent clogging with litter. Both cats tended to throw litter everywhere and the shower worked best. Also as fulltimers, replacing litter every day or two was out of the question. We used clumpable litter and scooped out the clumps almost with every use. Having the cat pan in the back had several more advantages. There is an exhaust fan near the shower. Even more important on days where we were in and out of the truck frequently, we would lock the cats in the camper so we did not need to worry about escapes or crushing a cat with a truck door.
The video mentions stuffing foam to seal the connection between the back window of the truck and the camper. For about $50 you can buy a vinyl clad foam "donut" that is designed to do this job and can be easily removed and reused.
