Trailer toosh rubbing

I wish it were Chewie's tail - that I can work around & prevent.... But, no, it's his rump! :) Looking at his tail, just to the right, there's a good-sized spot (about the size of a US dollar, rounded off to an ugly oval) where he's rubbed off hair, and even had some dried up skin there until I put some creams on it ... He's doing it in the trailer.. Two horse, slant load C&M. loads like a dream, and behaves like a saint going down the highway ... I can load him without the divider put up, but he moves around enough to make my truck hard to drive. So I started using the divider, loading him "up front". Turns out he's leaning on the right wall of the trailer, and putting that rub-mark on his toosh.

Do I put on a sleazy to trailer him good distances? We're working with a trainer in Austin, 2.5hour drive about twice a month... so not using the trailer isn't an option... hauled with an Explorer Sportrac, so I don't know if I can load him "in back", and still get any pull from the truck. Don't know if he'd rub loaded in back, either....

It gets pretty hot here, so I'm concerned putting a sleazy or sheet on him would make him overheat.. it's not much "stop & go" traffic.. I'm mostly "on the go", 60-65mph... two lane roads with moderate traffic...

Ya'll with the show experience & hauling experience... help me out! :)