For polishing the scratches out as good as poss.
CarPro Ceriglass Kit
Preferably with a dual action polisher, and a Rayon pad for applying the polish.
Take it steady, do it twice or three times, keeping heat down, rather than just doing it heavy handed once, as the heat can distort the glass.
I did my 10 yr old Clio182 screen and after three sessions, one after the other, which was what 1.5 to 2.0 hr work, it looked like a new screen.
As Danger says, look at cleanyourcar for the Ceriglass kits