.... From a ladies perspective....
If I drive the car regularly (or even rent one) I know the mileage within a thousand (first three digits anyways).

535i = 183,xxx
XJ6 = 127,xxx
Trusty minivan = 124,xxx
Daughter's Kia = 81,xxx
Son's Taurus = 62,xxx
Aurora I rented in Hawaii = 3,122

Get the picture?
Seriously, how do you stay on top of your maintenace and oil changes? What are you looking at each time you look at the dashboard? Do you ever figure up your gas mileage? I guess I assumed anyone who drove a car knew a ball park figure of their milage, specially someone who loves there car like I love my BMW.