45mm Standard
+7=52mm
This is the place I got mine (23mm for rear with E65 offset wheels)
http://www.************************************************************/productpage.aspx?pid=102089&name=H%26R+Trak%2b%c2%ae+Wheel+Spacers
Also, you will need to take off the rounded bolt shoulder from your existing wheel bolt and put on the new bolts
Good luck,
Ed