Just remember the little mechanical bike distance recorders with a little cog wheel on the end that clipped to your forks with a little spike on your spokes that hit the cog on every revolution? Click, click, click, click....
Or in some cases click.........click......
click...
As much fun as when the first thing you did when you got a car was go to buy a stick on rear windscreen demister and wire it dubiously to whatever live feed you could find in the rats nest of wires under the dashboard.