I've just painted my GRP air deflector. It has been lacquered, sanded back to an even matt texture with 1200 wet and dry and then rubbed with rubbibg compound to a slightly gloss finish. How do I polish it to a full gloss finish?

Keep rubbing! sounds like another dose of compound followed by a good wax should get a good shine. Are you doing it by hand? If so do the compound all in one direction in short strokes. I can get you the name of a good sports therapist to fix the almost inevitable tennis elbow

Caber

rub it with a finer grade compound, T cut works a tread, but requires some elbow grease.

in finer grades will get the lacquer smooth and shiny