Originally Posted by cdufault
I apologize in advance if this is irrelevant. On my 1977 airstream Argosy motorhome the cover for the seat back and the bottom cushion is one piece. There are zippered pockets for the seatback and bottom cushions. The fabric in between acts as a kind of hinge. Two slots in this 'fabric hinge' allow seatbelts to pass through (this is a motorhome after all.) At night, I wrap this all up in a thick foam mattress protector. It is very comfortable.
That seems like a better design. On ours the back cushion is actual two pieces. One narrower one that's snapped to the wall, and another taller that's vectored to it. I guess this type of design doesn't allow the back and button cushions to be connected.