Pretty much what MINICooperMurph said. But, to add a bit more information:
My original '04 Cooper came with 7 miles on the clock; my Feb '07 registered R53
MCS (although it was built in June '06) came with 15 miles showing on the clock. I've just collected a new car for work and that came with 7 miles showing as well.
Hope that helps.
Tigger.