If you don't maintain it. It will dry out and oxidize. Keep it sealed up and protected.
Yeah man, this is exactly why I asked this because maintenance would be a lot less costly then having to replace both headlight housings. And the whole restore thing seems like a several step process so if Waxing will protect them then it's a piece of cake to do while i'm doing a full wax which I do 3-4x a year.
I should mention that right after I posted this I was in pep boys and laughed because I saw a product I had NEVER seen before. It was by blue magic called headlight SEALANT. They had another product called headlight RESTORER which is obvious as to what it is...but I had NEVER seen a headlight SEALANT prior and like a day or two after I post this I saw it from blue magic in Pep boys..lol. I did some searching online and can't find any reviews on it but I know blue magic make excellent products so I may end up trying that too....anyone know of this product?