I'm detailing a Lincoln MKT and a Mercedes S63 with a retractable glass roofs. How can I find out if certain vehicles have a tinted glass or film tint on the roof? I know some of the Corvettes with glass roofs has a tint film on it. What is the best way to remove the water spots from either of these types of Glass Roofs? Also what is the finish on the edge of these retractable glass roofs. Is that plastic? I noticed that there is some bird dropping etching going on that. I didn't want to start polishing and create more problems.Thanks