Black roof surround

Now back in the Doedogne, I have spent the majority of the day in temperatures from 22 - 29 degrees cleaning the roof of my Broadway. The swimming pool area above the cab is very difficult to get clean because of the water continuously collecting there.  The white is now white but the black is matt and dull. I re-read the posts about the black roof light surround, washed it and polished it but still it was terrible. Then I remembered a friend who recommended WD40 for all of the panels on his motorbike. As a result I gave it a try on the roof side of the rear panel and in an area the wouldn't be visible on the front panel and so far I am very pleased with the result. 

My questions are does anyone know of any reason I should not use WD40 on GRP. Do you actually polish the roof.

I know you shouldn't get WD40 on decals as it softens the adhesive and they'll come off, not that you'll have any decals on the roof. It's also good at removing black streaks.

I too used WD40 on the black surrounds - it certainly brought the shine back initially but they seem to be dulling down again - are these not decals though?

Hello, I have had the same problem with the black surround on my Broadway , I known its a pain in the rear, what has worked for me was to wash and dry the black and then give it a T-Cut and cleaned it off and then I used a product  called K2 color max (black)which I got off E-Bay it as seemed to do the trick I did it the beginning of March and it is still shines.