If my car is registered with GovCorp, they technically own it through the registration and the license plates. Why, then, does the Royal Registry de Jure not own my car when I register it with them?

Answer: If you surrender the license plates and deregister your car with GovCorp, the vehicle is considered lost cargo. Once you register it with the Royal Registry de Jure, it becomes a private vehicle owned by an individual, rather than by the registry itself.