Re: bits of your car not working...
The Nintendo Wii's marketplace. Anything you download is for that machine only, and for you only. If you sell or give away your Wii, the license demands you wipe it first, but you don't retain the rights you've paid for.
Consider: I have a black Wii, you have a white Wii. We both have installed Ocarina of Time, and nothing else. We want to change colours, so we swap. We are required to wipe Ocarina from both of them, and then buy it a second time if we want to play it.
It sounds like the same is true for Tesla; if we swap cars, we both lose $8000 of features. Aside from artificially enhancing the company's profits, what sense could this possibly make?