i had a 10 mm front and 12 mm rear... (the car is also lowered...eibach pro-kit).
automotive wheel spacer dr-system h&r trak+
stock # 07-B9 (112/5)
item # 2055665 (20mm) (front) ... # 2455665 (24mm) (rear)
*(equals 10mm or 12mm each side)
the bolts are 1/2" longer than stock and are supplied through h&r.
cost: $200 ish
without spacers:
with spacers: