Help windsheild
Mix a little of that in a bowl with some water so it's kind of like a gritty paste. Take that, with a scotch pad and start buffing away at your window. Put some elbow grease into it too. Then wash it off, and it should solve your problem.
I know this sounds completely weird and random, but it works. I've tried it myself. Got the tip from a old friend, muscle car guy. He swears by it. And if it doesn't work, then you need to either replace the windshield, or have the scratches removed professionaly.
Oh, cover the painted surfaces of the car (like your hood and doors) with something. That, and it would probably be good to get a good coat of wax on the surrounding painted surfaces too, just in case you get some of that barkeeper's friend on the paint.
Good luck!

