In discussing the boundaries of animal sentience, the most important question is whether they can feel pain or distress.

So whilst a car's ability to sense and react to its environment may be at least as sophisticated as that of a plum tree, it's hard to see how it would meet the legal threshold for sentience in the same way that, say, a lobster does.

More to the point - if Musk genuinely believes that his cars are capable of suffering, why isn't he doing anything to prevent them from being harmed?