Stunning interior to the new A8 but the finger prints on the touch screens are annoying.

Microfibre cloths are OK but they don't get rid of the greasy marks. It needs some form of lens/screen cleaner

Audi cannot answer and I am reluctant to use product that might end up damaging the screens.

Any help would be appreciated

Bob

Hi Bob, you could try Aldi or Lidl glasses cleaner wipes - you get loads in a box and quite handy and reasonable. 
I've not used them on a MMI touch screen but have used them on expensive camera lenses, tablets, phones, standard MMI screen,  Oh and glasses. 
Thanks
Mark