How would one go about cleaning your dirty headliner? what shampoos/soap materials would you use?

whats good for taking out dirty grase stains?? clean green??

I would your a mild solution of apc with water, rub and wipe with a microfibre cloth. Careful not to soak roof lining as it may lose its stickiness and begin to sag

I used Sonax Interior cleaner....cleaned it up perfectly!

A very mild solution of APC (20:1) and either a clean microfiber or a soft clean shoe brush. A teaspoon of Easy off Bang mixed into a 1 litre spray bottle also works really well on roof linings.

Lightly mist the roof lining and then work the APC or soap into a light lather (foam) before wiping it down 2 or 3 times with a clean damp microfiber cloth. Sometimes the roof lining can get a bit 'fluffy' depending on the cloth/brush you use as well as the type of material on the actual roof lining. If it goes a bit fuzzy you will need to get a packet of disposable razors (BIC or similar), remove the moisturiser strip and then 'shave' the roof lining to get rid of the fluff. It will take you a good 2 to 3 hours from start to finish (plus another hour if you need to shave it), but the results are worth it!

Leave your car parked overnight with the windows cracked slightly to allow the roof lining to dry completely

thank guys, much appreciated