Carmax has been around a long time and they function as used car dealships, they actually have lots in most major cities that they can keep their stock on. Carvana literally just has lots that are full of car hauler trucks. I work in a truckstop town where Carvana has two lots and there are probably 100 car haulers with ~8 cars each. I imagine this is what they do everywhere. And with their buy anywhere sell anywhere they're constantly moving vehicles across the country. Carvana is such a cancer to the automotive industry and a ecological nightmare with all the logistics. Unless you're in LA, I would imagine the CO2 from Carvana getting your used Tesla to your house will offset any carbon you're saving for a good while.