My fibreglass sills are suffering from stone/sand abrasion due to road rubbish thrown up from the front wheels. I cannot cope with the full respray treatment at the moment so I was hoping there might be some sort of 'T Cut' type product that would reduce the visual impact in the short term. Any ideas welcomed.

fill them and then apply a strip of vinyl in a colour of your cchoice no need for paint and a locost option