I like how this roof is progressing. Looking good! As far as the window goes, I think maybe the luxury barges had glass windows, and the intermediate vehicles had clear vinyl windows. I had a 1966 Dodge Coronet 500 convertible and it had a vinyl window. My current 1968 Imperial Crown convertible has a glass window. As a side note, I never unzipped either one of them. They both went down into the top well with no problems.