i polished some etching out after someone had made a balls up of it a few year ago..i used jewellers rouge, a bit glass cleaner and a small polshing head on a drill..the etching was quite deep so after polishing it there was a small 'gold fish bowl' effect in the glass but no etch..depends how deep the etching is as to what finish you would get..but either way it will look crap especially if it on a concours car