Funny you said that. When I first changed the plugs in my GMC, I dropped one and it landed on top of the frame. I left it there until I was done, and when I looked for it somehow it has disappeared. It wasn't on the cement pad and after a while I just figured it dropped out on the road somewhere over the next 100 thousand miles.
The last grease job I gave it before it was sold, I was swinging out from under the truck by grabbing onto the frame and my hand landed on the lost plug. It had laid on top of the frame for 100 thousand miles and never vibrated off.
That’s cool