By the way if you change your rotors you can fit 17" and even 18" on a E21. 18's on 35's and 17's on 40's. If you don't believe me check this site out. http://www.adequatebass.freeserve.co.uk/ but this guy kept his 4X100 bolt and banged in the wheel wells .75 inches so the offset changed. It looks pretty dope. But i would suggest changing your rotor though saves time and improves performance.