It does and they do. A used car is cheaper to source than a new one which means it can be sold to more consumers at higher margin.

Every taxi I rode in the Bahamas was a 2nd gen Jeep Grand Cherokee with the CEL on.

The bottom exists, but it’s not here.

I don’t doubt used cars are shipped out of the US, but I’m pretty confident quite a few cars are junked in the US as well, as any junkyard demonstrates. I’d be pretty surprised to hear that junk cars (a subset of used cars) are shipped and resold.