My drivers side wiper blade must have had some grit under it and it has etched the screen with fine scratches that now flare with oncomming headlights. Windscreen O'Brien say the screen has to be replaced but there must be a way of polishing the glass to remove the scratches.

There is a way but it's just so much easier to change the windscreen. You can do a google search for cerium oxide if you're really fond of your current windscreen.

There is a way but it's just so much easier to change the windscreen. You can do a google search for cerium oxide if you're really fond of your current windscreen.
yeah "Jeweller's Rouge".

Can also try fine wet-n-dry eg 2000-3000 grit under running water but its gunna take a long time. Buffing with a power furry bonnet would be good too.

depending on how deep it has scratched the glass you may have to get it replaced,i tried all sorts of glass cleaner stuff but the scatch stil showed,240 bucks for a new windscreen it may cost you.

Same thing here cuppla years ago. I ended up choosing O'Brien to swap it for 240 bux incl labor. Apparently those magical creams don't make much diff.