Originally Posted by euro driver e34
Nothing!!!!!!!!!!!! U.S. cars are more restricted than other models throughout the world. For some odd REASON, U.S. thinks by slowing cars down will keep the people on the roads safe instead of strengthing laws on liscenses. Also they restict the exhaust and govern speed. Thus, they are buzzkills and should be slapped in the nuts!
Ok.That make sense. That's the reason why Euro M3 is different from US M3.
There's one article, US version M3 is just like a tuned 328i.