Interesting legal situation- Tesla sold the car on with the feature enabled (because it still shows and works on the car) but then removes it in the future when it's in the hands of another owner after the title has been transferred? Seems like a pretty clear violation of first sale doctrine. I can't sell you a car and then go "whoops, I meant to take this engine out before I sold it..." You have the responsibility to verify what you are selling is in the condition in which you want it sold.
What an insane world in which the configuration and value of a car cannot be determined from physically looking at and testing the car.
In the situation I am describing (which has happened to many people)
Person buys car from tesla, then sells the car back to tesla "later" Tesla is the owner of the car when its traded back into them, and turns off FSD on the vehicle OTA. That doesnt happen for some reason on the vehicle.
Tesla sells car to auction, "some dealer" buys vehicle, advertises it for sale, person looks at it, sees "oh wow this car has FSD" (whether dealer advertises it with FSD or not). Person buys car, during ownership transfer, tesla "corrects the mistake" of the FSD not being removed when it was in their hands in the first place. Person screams bloody murder, and posts everywhere (including here) that "Tesla removed my FSD", they were not entitled to do that!!!!@#!#@#!@#! (even though the car passed through tesla hands and they were entitled to do that, it just took a while.
The above situation can happen if the original purchaser bought FSD. It can also happen if the person just "HAS" FSD but never purchased it. That has happened too (people having FSD but never buying it, the free trial never expiring and the person trading the car in "as is" as all cars are, and FSD is on it then, but never paid for.
Anyway, the point I was making is, there is NO WAY to know the chain of custody of a car purchased on a third party lot, so it doesnt matter what software feature is there or not, if one is buying such a car they should price it as if it doesnt have FSD, because they dont know if it will stay, and there is no way to find out if the car ever passed through tesla before you buy it that I am aware of (I am not a car dealer though).
You asked me what the difference was, so thats why I am spelling it out. If you buy from someone who bought it from tesla directly (new), and they can show you they purchased FSD, then you have certainty it will stay there. Other than that, there isnt any other way I am aware of to get that.
Dancar knows all this though, I am virtually certain, so this is just another "Im bored lets have a discussion" thread, most likely.