After looking at 6 used M3s I found one with a clocked odometer and one that was tracked heavily. In the latter case the selling BMW dealer doesn't know this and the car is "certified".
Now I am leary. Can the local DMV be of any help? I heard from a friend that sometimes stolen cars can have good titles and then get taken away if you buy it unknowingly, So especiailly in the case of a private sale, how in the world can you tell? How do dealers protect themselves? It appears that original owner and club enthusiast owners with reputations might be safer bets than some guy with an ad on the internet.