Well i had a go today at my rocker cover with a dremel and brass wire wheel. didnt do a lot to the cover but worked wonders on my exhaust manifold till the wire wheel wore out. Think i`ll have another go at it when i get a new wheel. And work out a better way to clean the cover, Want em shiney, but as i live in a flat it has to be done on the car , unless someones got a garage.lol