I have used a bath towel for over 30 years and it protected all my seats from cloth to leather . I never put it on the back rest only on the seats.
steal some from your wife stash , she will never know they are gone
When they wear out, you could put in better wheeling seats. That's my plan. I'll also probably sell my rear seats (2 door) brand new or damn near new because I don't really want them. I'm doing a custom rear compartment mod.
Would second Wet Okole, had them in 4 cars and trucks now, they fit great, I find them comfortable, they add a bit of padding to the seats, and they are waterproof. In addition, they have held up pretty well to my 85 lb dog jumping in and out, walking around, etc, in the back seat. They are not particularly cheap, but I think they are comparable to the other custom fit options in price, and the quality is defitinely there.