Cleaning the rag top on 2005 Ford Thunderbird

I have a Ford Thunderbird Convertible 2005. From the rag top being folded back there are some visible black marks (oil?) on it. I’ve tried to remove with soapy products but to no avail. Is there s specific product or process I can use to clean/get rid of these marks. The rag top is a rich tan color

Are the marks on the top itself??

If so Raggtop brand products are your friend. Not an advert, just real experience with the product.

Use soft brushes and lots of clean water for rinse. Good Luck!