Have you not spoken to sitrep? Then again, if you spent more time on mw2, you'd have had answers by now!

Anyway I think it was JPC who said the vw leather has some kind of plastic coating or something so not a true leather surface.
Either way, I've had good results with gliptone and even better results with LTT leather care. Buy a proper brush to work in the cleaner.
The last I treated the car however, I used diluted APC, agitsted the "leather", wiped clean and treated with poorboys natural look dressing which also gave a great look.