How to clean my headliner?
I apologize if this sounds ridiculous, but my light grey headliner is extremely filthy - especially the back half since I always drive with my windows down. It's honestly almost black in some spots back there. I'd like to give it a good cleaning, but I'm unsure of the best/safest way to do it. I don't want to soak it to the point where it starts to separate and sag. I don't want to stain it with harsh chemicals. I don't want to scrub it to the point where it starts to fall apart and look fuzzy.
Maybe I'll start by vacuuming it with an attachment on a hose and see if that pulls any of the dirt out. If that doesn't work, does anybody have any recommendations for chemicals to use or cleaning procedures to follow to get the best results so I don't damage anything?