I thought it was worth reposting what Greg told me about the 323 sports package wheels. Maybe it has something to do with the reported floatiness/shakes reported by some owners. Greg was commenting on the replica MAS 16 X 7.5 inches, which is .5 inches wider than the sport package wheels. Well, this was his comment on why 16 X 7.5 is better than 16 X 7 for 225 tires (note he said 16 X 7 may create too much sidewall flex):
Yes, for 225s (sport pack), the 1/2 inch d0es make a diff. BBS for example (and BMW) have long preferred 7.5s (or 8s) for 16" 3ers--I'm sure always assuming 225mm section tires are being spec'd for aftermarket wheels, so it's (mildy) surprising BMW chose 7s for a sport pack (their $? Nawh!). 7s best for 205s, but not 225s--too much sidewall flex for optimum response. 7s are w/in specs so perfectly safe and perhaps better ride, but not optimal for handling. 8s on the other hand handle even better, but sacrifice even more ride for some tastes, so 7.5s perfect compromise. Whether the modest increase in width is worth your $ is another matter--up to you! Good luck!"