Millennial anti-theft device

[Toolmaker51]

...........It all gets me to thinking on my stick/ manual transmissions over the years, including several motorcycles. Let 105 lb girlfriend drive my Sportster. California wasn't a helmet state yet, she wanted to, and already rode decent size dirtbikes.
"OK, but only if you can start it".
No cell phones back then, need be how on earth I locate her happy butt on my treasured putt? If you've ever heard Richard Thompson's "1952 Vincent Black Lightning"? you can visualize my Kate Jackson lookalike riding, just with yet longer dark hair trailing behind, running it through the gears.
Horses or motorcycles; nothing more beautiful than when ridden by a woman.

Believe me, when I said 'lookalike', I meant exactly. Other than 3 years age difference, they'd have been indistinguishable from birthed as identical twins.