When I was a kid, many years ago, my parents always bought used cars. We always would check under the rear seat to see if there were any toys left behind by the previous owners.
Then when I bought my first new car in the 1970s, I happened to look under the rear seat and found a spare window crank handle.
So all of those years, what we thought as kids previous owners leaving stuff behind might have been from the factory.
The only thing that works on a RV is the owner...