bg on the inside of the windshield for sure. The glass could just be pitted, in that case there isn't a hole lot you can do. I would not suggest using a razor blade, but clay really well followed up by sealant/any glass treatment. A product you might want to look into is glass parancy. It is a permanent glass coating which fills and levels glass creating a 3 year warrantied glass coating leaving your glass crazy hydrophobic as well as crystal clear for years to come. Hope this helps!