offset is too low mate. on Mk5s Bentley rims sit about flush and they are 9J ET41
9J ET 41 sits the same as 8.5J ET35 or 8J ET29
in other words, compared with 8J ET20 and 8J ET24 the rims will poke by 9mm and 5mm respectively. arch rolling won't make any difference if the wheel is outside of the arch in the first place. there may be enough metal at the back of the wheel to machine down and increase the offset, but i would contact a reputable wheel refurbisher and ask them first.
short of that it's a no go i'm afraid.