I had a BMW with encrypted CAN or very similar to what that would be. Would refuse to use a new module unless you had the dealership key. Which my mechanic managed to get from his friend at the dealership but still...
That started with the high intensity headlights. They were such a high theft item that when they're disconnected from the battery, they go into a locked state that requires a dealership to do the unlock.
Needless to say, never again