Looking at it from the original buyers perspective, When they sold/traded in their used Model S to Tesla did the price they get take into account the self drive feature, or do Tesla pay the same trade in regardless of software features? If Tesla aren't buying back the feature then it makes it even less enticing to buy it on a new car as it has 100% depreciation! If they're paying for it at trade in then removing it before they sell it on then thats kinda fair enough its a bit like a dealer taking in a car with fancy wheels and putting stock ones on before they sell it on, sucks for the used buyer if they then have to pay full new price to add that feature later but... Although in this case it seems the issue is that Tesla sold a used car with a feature and then decided to take that feature back, which is theft in my book pure and simple.