I was thinking something like toothpaste or brasso as they are fairly mild abrasives but I dont want to mess it up.
Hmmm, sounds like far too much effort. I reckon it'd be easier and less time consuming to just replace the window altogether. I never liked the slatted grills anyway, a plain tinted one would look much better.
Yeah I've been thinking about replacing the window with a plain clear one anyway. It's a pretty awkward shape though with 16 holes where the push rivets go. From what I've heard acrylic can be a nightmare to cut and drill. Perhaps I'll have a go and post the results.A flat piece of acrylic would be very cheap, certainly not worth the effort.