Not sure if this has already been discussed here but, apparently, a number of reports say that Tesla has removed features (via Software Upgrade) like Autopilot and Ludicrous Mode from used Teslas
after they were purchased by the owner who bought the car with those features.
Here's one from
Motor Trend where Autopilot and Full Self Driving modes suddenly disappeared (without telling the owner).
Here's another from Jalopnik (
HERE and
HERE) where as a result of an "audit" of the car subsequent to purchase of a used Tesla, features were removed because Tesla claimed they were not purchased by the used car buyer. There has apparently been no official response from Tesla as yet.
If they can do this then this may be a kind of paradigm shift in used car buying where the buyer of a used car may have a car with different trim levels / features than the previous (original) owner. This essentially means that car options are purchased subscription-based that attaches with the owner rather than as products that attaches with the car.