Blackfire Wet Diamond All Finish Paint Protection isn`t formulated for glass, but you shouldn`t have any problem applying it to any painted surface. You can try a test spot on glass and see if it holds up. You most likely will not have any problems applying it and wiping it off, the only thing that might be affected is how long it is going to last. It might not stick that well to glass, since glass is structurally different than paint.
I would recommend McKee`s 37 Glass Coating, if you want something that is going to last and keep the glass protected.