Can't seem to clean the grey bit. It just seems ingrained dirt. I have tried claying it, as suggested by someone else, but still nothing. Any suggestions. I even used a bit of Jiff in a very small part and still won't shift it. If it won't clean I was thinking of possibly sticking some carbon fibre over it ? I think it may compliment the colour of the car...maybe. btw, I'm not after any comments on the chrome.......I've heard it all before.