RE: Speedometer Repair
The interesting thing that Ramon's comments points our is that one of the
things that hasn't changed over the years (since to introduction of the
speedometer early in the days of the automobile) is the way the dial
type/analog speedometer works.  With the exception of the cars with the
digital instrument clusters, the spinning magnet inside an aluminum cup is
still the same technology.  Elegant solutions to a problem are just that,
little or no improvement needed over time.