
  I was wondering if anyone can shed any light on just how it is that these
electronic odometers remember the total elapsed mileage?  What kind of
memory is stable/reliable enough, non-volatile enough and independent enough
(of outside battery power) to last say, 10 years or more, in the life of a
vehicle?  I'm amazed that anything like this could be expected to work for
this length of time (especially in light of all the gizmos I work with that
are doing good to work for 2 months without breaking down somehow).

Side question:  how about the legal ramifications of selling a used car with
a replaced odometer that starts over at 0 miles, after say 100/200/300K
actual miles.  Looks like fraud would be fairly easy - for the price of a
new odometer, you can say it has however many miles you want to tell the
buyer it has.

Thanks for any insight.
