Comment by defrost

Yep .. quite a lot of them, for substantial periods of time.

Contrary to expectations it didn't seem to affect the tubes or tyres, shorten lifespans, etc.

FWiW I grew up in fairly remote parts of the world and we repaired pretty much everything as much as possible with what we had - aircraft, helicopters, radios, etc.

My first thought, to be honest, was "Why not just grab a spare spark plug from the boot?"

I'm guessing not so many people stock spares when driving so much anymore.

You can also replace a blown out tyre with a hard wood skid if pressed, weld up broken steel with car batteries, stuff tyres with grasses, etc.

* Bush Mechanics: https://www.youtube.com/watch?v=P6foUHyfX3Q is fun.