hello there Gil, if and only if the panel is GRP (glass fibre)you can polish with rubbing compound I would reccomend either mirror glaze or farcella both can be obtained from either grp/boat/chandlers etc or some automotive paint suppliers. of the two I would prefer the mirrorglaze system ,first the rubbing compound then the machine glaze, then the wax polish, farcella also have a similer system, whatever you do I wouldn't reccomend using the wet & dry as the gelcoat is very thin on these panels and you would still need to use the compound to get rid of the fine scratches left by the wet & dry, apart from that just to get the shine back you shouldn't need it. I do know what I am talking about re GRP as I spent nearly 25 years designing and making moulds for caravanette hi top roofs if it is a plastic panel ie ABS capped I wouldn't know how to get the shine back,....Mark