I thing the console builders are to blame. Most PC games don't have hidden costs, and you are the ruler of the PC, more of less. Since Sony's action to remove the otherOS option I'm not fond of the consoles anymore. Customer who are using console have more or less sold their rights to the console maker. In the end they have the power we as a customer has non (by accepting te EULA you've sold your console soul to ...) They can remove anything they want to and even ask money for something that used to be free.

If it's a Philips product (of which they would have been capable of). It might be that friends of the evoluon (the Philips "flying saucer") might be able to help you?

This link gives some extra information security thoughts about EFI.
http://blog.thesilentnumber.me/2009/01/efi-hidden-threat-to-computing-freedom.htm

I don't see any advantage when it would be encrypted or DRM would be used.
As a garage needs to do tests they'll be able to change values. If you get the keys credentials from a garage one can do the same.

It should just be impossible either change values for certain devices like brakes when the car is running or they should be reset when a diagnostic device is detached.

This new item wouldn't be an issue in most industries.

If an employee of a certain car producer drives to work with the car of the competitor no one wouldn't even be bothered. It's a fact that this happens.