Tell me about it, I had a 2007 1 series BMW and its transmission computer became dead. Now, I was quoted 4000USD at the dealership (the car was worth about 5000 at that point). I went to a third party specializing in automatic transmission and they almost could do it by swapping the computer from a crashed car.
Turns out it needs an encryption key (who only the dealership has) to get the car to recognize the computer, otherwise it won't even start. I sold it for parts and will never have an automatic BMW again.
According to the transmission guy things have only gotten worse with newer models, particularly Audi/Volkswagen and BMW.
However, the actual practice of applying the now-legal practice to something like you described is far above the technical skill of most automotive shops. Some tuners may be able to do it, so it might be worth asking around and doing some digging if this happens to anyone else.
One thing to keep in mind is that one person's spare part may be another' srolen car or car parts. Especially in Europe, stealing parts is a thing. Some gangs won't steal entire cars, but only break in and take parts according to a "shopping list". Locking components to one another helps to make stolen parts useless and acts as a deterrent.
Yeah my dad and my mother both had their cars broken into and both of their steering wheels stolen.
The door locks were surgically removed and nothing else was touched or ruined. They only removed those parts and went their way.
Then there should be a mechanism of being able to prove provenance of part and forcing the manufacturer to "re pair" components into another car without having to pay an absurd price.
Reminds me of a guy I met once. He ran a small auto repair shop focusing on a single brand (Audi, AFAIR). He had a special device to talk with cars' computers and a laptop for it with software and appropriate keys. He explained to me that getting this from the auto manufacturer would cost a small fortune; instead, what he did is contract with some Chinese people, who from time to time would RDP to the laptop and update whatever in that software that needed updating; with the interface that I think was probably second-hand also, it apparently costed only a fraction of what manufacturer would want.
Turns out it needs an encryption key (who only the dealership has) to get the car to recognize the computer, otherwise it won't even start. I sold it for parts and will never have an automatic BMW again.
According to the transmission guy things have only gotten worse with newer models, particularly Audi/Volkswagen and BMW.