I have a 68 bus but doing a later 5x112 wheel swap...On my Audi A4 Ronal wheels (16x7 45 ET), I clearanced the hub area on the wheel til the grease cap fit in, I got the rotors to fit but will bottom out on the lip of the grease cap...BUT, this is about where I need the wheel to sit as any farther in and I wouldn't get the wheel center cap on....so it looks to be a 13 mm spacer and longer studs...does this sound right..I know some have installed Audi wheels without spacers in front, but what about the center cap