[FLYIN']

The training manual states that if you use seat covers the airbag sensors may not work correctly so they said to only use manufacturer recommended covers. For which I don't think they have a recommendation. Plus the seat heat would be affected.
I agree with the "grandmothers couch" comment as it is a shame to cover up the factory cover.
My dad had plastic covers on our Morris Minor 1000 when I was a kid. No seat belts then so would slide in the back seat when on corners.