Important fyi. The window frames are hard coat anodized. If you polish/sand through it, the color will be different because of the difference in color of the anodizing and the base aluminum. If you need to get it anodized, it is very expensive because of stripping stripping the old anodizing, polishing thebase aluminum and then hard coat anodizing. Unfortunately, I know this from my exprrience and it cost around $750 to get them shiny and scratch free again.