I got a bit annoyed looking at the corroding heat shield so I tried to polish it up with Autosol metal polish, although it tidied up a bit it just became a shinier mess than it was before. I decided to paint it, I saw some High Temp Paint in Halfords so bought a rattle can. It is recommended to clean the surface with thinners or suchlike, of which I had none. I did have a Gunk degreaser at hand so wiped it down with that then rinsed off any residue and let it air dry. So remove the three 12mm bolts, two up above and one below. The lower bolt was a corroded mess on mine, it was no longer hexagonal so only vice grips inside a cheater pipe (Arcan jack handle) got mine off. I just sat the heat shield on a bit of cardboard and proceeded to spray it. Now its recommended to paint onto bare metal, my first coat was therefore my best. I decided to give it a second coat but it basically left something like a fine powdery residue on the surface. I thought that it may cure eventually but weeks later after building engine temperatures up gradually it never quite cured. I simply brushed off the existing 'residue' with a soft paint brush a fortnight later. Today (6weeks later) its still looking much better than it did before.