Check with your local garage if you live in a state where safety or emission stickers are affixed to windshields. In the 90s some GM cars had plastic coated windshields that required the use of plastic razor blades (it didn't well) to remove the old stickers. Most garages have a handful laying around in a tool box somewhere. I have used them with a little heat from a hair dryer to remove signage from the out side of commercial vehicles.
Earl
