It's another example of some pretty short sighted thinking on the part of Tesla.
Their used car experience is laughably bad to the point of insanity. Basically insist on a deposit of £4k to buy a car you can't even see decent pictures of and that they won't guarantee the condition of, then kick up a massive fuss if you try and get that deposit back when the car is in shocking condition. Not even an option to see the vehicle in the flesh before commiting to buying a car often well in excess of £50k.
Then on the other side though, the best used car warranty offer from a manufacturer by far with 4 years of cover, which is frankly incredible compared to the competition, where you're usually lucky to get more than one year on an approved used car.
They could outsource the entire operation to a third party to manage for them if they really don't see it as core to their business, and still realise more profit and more goodwill. If it were me, I'd transport all used vehicles to a single site somewhere in the middle of the country, take excellent pictures of inside and out and allow people to view them all in a controlled environment. They can still insist on taking deposits online and don't even need to offer test drives, just let people look at their £50k purchase before having to make a commitment to buy! You wouldn't need more than one or two members of staff and a secure car park, but you'd give people the confidence to actually buy the cars and so could charge enough over the existing used prices to pay for itself comfortably I'm sure.