I had mine tinted on a previous RV, and one window did get fogged, so replaced it. But all the others (and the new window) are fine (friend owns it now, just camped with them this weekend) and it's been about thirteen years. Also have some friends with another SOB, and all their windows are fogged, which may be due to the tint, but who really knows.
I've resisted tinting the windows on the FT, but may eventually tint the outsides, just not sure how long it will last out there, and once they start peeling, it will look terrible.
7 years with limo tint on all windows behind drivers area no trouble.
Pamela & Mike