I have had success in removing scratches from caravan windows with brasso, make sure that the windows are washed and dried beforehand then put some on a soft cloth and carefully polish windows.
"Greygate" plastic polish is what is used in professional circles for cleaning/polishing plastic transparencies. It is very high quality. It’s available via various sellers on eBay or via Greygate Chemicals who are here
They can explain the technicalities of why metal polish and other abrasives are not the best option (even though they can sell you those if you want)
They’ll quote their quality and performance by customer base, one of whom is the MOD/NATO who issues it for polishing Perspex/acrylic transparencies on aircraft. It’s totally true and I’ve spent many hours doing so in the past.
I’ve used it since on caravan windows amongst many other things and just bought a new sealed 100ml bottle for £4.99 on eBay, it'll last years.