I got my E90 M3 from a gentleman that had it advertised "take over lease" on this forum. The payment was too good to be true. He turned out to be a legit seller.
I got the car in May of 2012, and it's a 2011. The car had 17200 miles. Now, it has about 19800-Yeah, I hardly drive the car.
The reason I wanted an E90 M3 is the same reason I always wanted a 4 door E36 M3; but, couldn't back then, and instead I was stuck with the 2 door. I just liked the flexibility of the 4 door.