In fact, just this discussion made me decide to look for some UV resistant tough marine vinyl and fix my seats.
Edit: had a look on the local market, and what do you know. Someone's selling this fabric below for $15 a yard, 54 inch wide. Seems like good quality, the only problem is on the North-East side of Toronto. I don't want to drive there just for this. If it was just a little closer I'd get some.

