New Pop Top Stain

[pokenhen]

Hi all, looking for a bit of cleaning advice please. We've only had our van a few weeks and this weekend we had the pop top open for the first time. As you can see from the photo there's a fairly large dark mark/stain on the side and I can't see anything obvious that would have caused it - there's no other marks anywhere and like I say the pop top is brand new and the van's kept garaged. The company that did the conversion has already agreed that they can replace it under warranty so all good there but before we go down that road I might as well try cleaning it. Does anyone have any advice on what cleaning product might work - we've tried with a damp cloth but no luck.
Thanks

 

[Merryman]

Had also a stain on first opening up. Installers said it was likely to be fibre glass dust. Give it a good hosing down. Possibly a light soap wash on the inside, maybe fabric from the carpeting. Hope that helps.

 

[DXX]

Try Vanish, seems to shift most stains.

 

[Shaun Witts]

Try to brush/vacuum it when dry before trying anything wet.

 

[Mocko1962]

Milton cleaning fluid diluted . seems to clean anything my wife throws at it