What offset is the A8 using with the 19x8.5 12 Spoke wheel?
What tire size?
Here's a link to a great Audi/VW wheel site; the 19" 12-spokers are about 1/3 the way down, called "Audi A8 19". The nineteens, according to that site, are 8.5" wide 5X112s w/40 offset. This site also shows stock tire size as 215/35-19 but the tires are 255/40-19 on mine w/the 19" 12-spokes . Can't look at the manual because the wife just took off in it!
I guess you know the 12-spoke wheels came in 18", too, so be careful not to look at the wrong specs (ask how I know).
Need to check what spacers I will use to get the right 'pushed out' (fender flush) with the 40 offset.