Here's a nugget of trivia.. I once had a Volvo with a white-ish headliner. I took it it for a sunroof problem, and when returned to me, it had a greasy smear on that white fabric. I had them look at it.. "no prob", the guy said. Goes into the garage, comes back with a can of brake-pad cleaner. Squirts some on the stain, touches it (not rubs) with clean rag.. instantly gone. I was surprised. He explained that brake pads need to be VERY clean, to avoid squeaking, thus the cleaner for them is highly effective. One could give it a try, if you're feeling it's a greasy stain. No promises.. but maybe worth a try.