I used to know a guy who got an award from Securicor parcels (or whatever they're called nowadays) who got an award for driving 250,000 accident free miles - and that was about ten years ago and he's still there.
I know a few cyclists who are members of the 300,000 mile club - all of retirement age though.
And me........... I've been a naval chap, worked offshore, down south, USA, Canada and have been commuting weekly to London for the last seven years (lets says 48 trips a year x 7 years x 1000 miles) = 336,000 miles on that alone.
I'm 38 and reckon I'm probably well up there, or at least I will be if I manage to get a wee bit older.
Good question though and very thought provoking