Re: Cleaning stained vinyl headliner
I've never used it on vinyl fabric but on vinyl rub rails, winch handle pockets and so forth, MEK (methyl ethyl ketone) solvent has worked miracles for me. Dampen a clean cotton cloth with MEK and rub. You have to be careful because it will temporarily soften the plastic - it becomes a bit tacky - but that goes away in a very short time.
It's nasty stuff so wear chemical resistant "rubber" gloves and be sure to be well ventilated. It has sort of an ammonia like quality - catches in your throat if you breathe the fumes. It is highly volatile as well so you have to keep moistening the cloth with it.
Give it a try in the most inconspicuous spot you can - you may be pleasantly surprised at how effective it is.
I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.