If no one ever bought a new car, what would happen to the price of used cars?

There will be a glut of second hand cars and the price will fall dramatically. That is probably whats going to happen when the covid-19 restrictions are totally lifted;that is how i see it in the UK

Well there are alot of people out there that don't know much about cars so they will buy a brand new car and not have to worry about anything breaking. And you usually could get a better deal on a used car but it does require some knowledge about cars so you don't get ripped off.

If no one bought a new car or a new house, the US economy would COLLAPSE and you and your neighbors will be UNEMPLOYED.  The price of used cars will be the least of your worries because you cannot buy one.   As they often say, be very careful what you wish for because you might just get it!!

As that will never happen, wasting time considering it is pointless.

One Guess - The theory is called Supply and Demand. As available inventory rises prices fall, and vis-a-versa.