Re: Always read the software license terms and conditions
Perhaps there's a case here for a challenge to the terms and conditions on the basis that they are an unfair restriction to third party resellers of second hand cars.
The difficulty would be that it would probably have to be a class action and fairly complex, but it would be a good precedent to establish. As you say, though, a better result might be that Tesla takes the morally responsible position and makes the change allowing the software to stay with the car voluntarily.