https://www.youtube.com/watch?v=HnOPD2MOngU Here is a small engine whose timing is controlled by an Arduino. You vastly overestimate what can be done, and underestimate the intelligence and willpower of terrorists.
All you're achieving is making it harder for everyday people to work on their vehicles.
If you want to make every aspect of life feel like commercial air travel does at present, then sure, then play your ever-escalating game of whack-a-mole, but please don't speak as if the conclusion is so foregone. And don't pretend the benefits will naturally materialize (when history has shown that they won't). The cost of such a system is the only part of it that's guaranteed.
"The trouble with you Americans is you think every problem has a solution," it has been observed.