One problem related to tire sidewall has been reported for the 2000 BMW Z3. The most recently reported issues are listed below.
Both the left front and left rear tires have developed soft spots/bubbles in the sidewall. Authorized dealers claim damage from road hazard. I have noticed other Z3's with similar issues on these tires, and do not believe road hazard to be the cause. Direct correspondence to michelin remains unamswered. (tiresize: 225/50 r16)( dot number: tire size: 225/50 r16 ).