Everybody's entitled to their own opinion, and I agree with half of yours. I don't put anything on the inside. As far as the outside goes, I've tried the thing wax, and I've tried Rain-X. In my own experience, Rain-X has done a great job of keeping the ice from sticking to the windows. It forms, but instead of sticking and having to scrape it off, it just slides away. As far "not getting them back" after lenses turn yellow, you either haven't tried the right product, or didn't use it properly. I know Simichrome works. I've used it on several trucks' heads, and a few tails as well with better than expected results.

SL