Originally Posted by GregW / Oregon
While I prefer 19s, 18s are less expensive, tires are less expensive, the ride is slightly better, rims are less vulnerable to potholes and handling just as good with only a tad less steering response. However, if you decide to go aftermarket, the 19s will be easier to sell.
I've heard the pretty much exactly the same comment from a pro race car driver regarding the wheel choice (18" vs. 19") on another sports car on TV, but can't remember what care they were talking about...
I am not sure if I agree with you on the aftermarket thing though. There will be many E90 owners who will be dying to get their hands on either type of M3 wheels I think.