I'm also the third owner of mine; bought it with 6600 miles on it.
First owner had it for a year and traded it in on a Panamera in FL. Second owner was a Porsche guy that went to buy a new Porsche and decided to buy the M3 off the lot.
Pre purchase inspection was flawless, car was pristine and the story checked out so I snapped it up.
I drive so few miles/year that it will go to the fourth owner before it hits 20k miles.