Top cleaning & maintain

[pbanders]

My car (black) has a dove-grey top, which is dingy-looking, has a nasty oil/grease (thanks to my dealer) stain on the top, and has dirt or discoloration in the folds on the side. However, it works fine and probably can go for a lot longer. I've tried a couple of things on the oil/grease stain (including naptha), but it's still there.

Anyone have any suggestions for removing the stain? Once I get rid of it, I'm going to wash the top with one of the products recommended here, then use Raggtop to protect it.