My middle seat has had a few little tears put into it (which of course no children know ANYTHING about!!), and I was reading about the TMI Car Seat Covers. Does anyone have these and do they just fit over your existing seat? I just want to get something that will do for a few years without having to get the whole seat re-upholstered, because other than the little tears, they're in good nick. Any photos would be great too. What sort of cost are we talking about too? Thanks.