Thats what I figure 10 year tops without some serious polishing.

My windows have become dull IMO, and show internal crazing. You can
still beat the **** out of them and they will not fail, yet the view
IMO is less than desirable. If you have flat windows then use armored
glass. All mine are curved. However if I can get all new glass made for
3X the price of lexan then that is the way I will go. Like I said, I
will try to polish mine this summer, If it does not work then I'm
willing to shell out 5-8K to have custom Armored glass made for
RedCloud.

Joe