Of course there is. At least in my country, there is a formal legal procedure to get your car inspected and re-registered after any changes are made.

It voids warranty though, doesn't it?

But there's a procedure enabling you to do it. On iOS, there are procedures preventing you from doing it.

The car doesn't have cryptographic locks on its bonnet.

Unless it's a Tesla.

At least with a Tesla there's a healthy aftermarket using the motors and batteries for vehicle retrofits.

But neither does the car manufacturer actively try to prevent you from doing so.