I got some universal seat covers for the rear bench seat in my Toyota Highlander and another for the back seat of my Corolla when I was hauling my grand children to and from school. Can’t remember if they were from Autozone or Target but I’m sure all of the auto stores as well as a Walmart and Costco carry them. They were cheap and worked fine.
You could also use the moving blankets from Harbor Freight that sell for $5 to $7. I bought a bunch of them to use when hauling stuff and to cover Model A parts in my stash.
David Serrano