the best fix is to replace the section of cloth any good upholsterer would be able to do this finding material to match is the problem , a quick fix is to pick up a set of rear seats as these go cheaper than fronts but I'm not sure that the rears have a piece of cloth big enough to replace the worn piece in one piece , and while the upholsterer is replacing the cloth get them to replace or repair the foam as that deteriorates with use and the new cloth will get in the same state old stuff very quickly if the foams worn
Rob
