Bgreene:
Vic L is right sheet glass is best but its not cheap. In my opinion overpriced....
Overall the best option is to limit window size to what is needed and use sunbrella which is more forgiving as a boarder (wider the better) . I've had good luck with the this material ( .40 gauge) and 5 yards will cost less than one sheet of the good stuff. It is UV resistant and holds up well over time as long as you don't crease it. But that goes for the good stuff as well.
http://www.rochfordsupply.com/shop/T...nyl/index.html
They also sell a vinyl cleaner / polish keeps your enclosure protected and looking good a lot longer than just a quick rinse and wash but you have to keep up with it as it only lasts a month or two at a time. Application is easy enough so that's not a problem
[URL="http://www.rochfordsupply.com/shop/Adhesives_and_Sprays/Cleaners_and_Conditioners/Strataglass_Cleaner_and_Polish/index.html"]http://www.rochfordsupply.com/shop/Adhesives_and_Sprays/Cleaners_and_Conditioners/Strataglass_Cleaner_and_Polish/index.html[/U
Kamikaze