Just read an article that criticized poly headlights. Even when new they are only 83% effective, I suppose for light transmission. When they get old it drops to 50%, from yellowing, etc. The article also mentioned having them polished to restore doesn't make them like new.
I had a Mazda with glass. It was thick and heavy, and one still cracked. It was so thick I think it had to limit light transmission.
I had a Mazda with glass. It was thick and heavy, and one still cracked. It was so thick I think it had to limit light transmission.