But just like with some computers where you void your warranty by cracking it open and performing upgrades by yourself, all the car manufacturer has to do is s

But just like with some computers where you void your warranty by cracking it open and performing upgrades by yourself, all the car manufacturer has to do is sell their cars with the same requirement. You start messing around with the internals and a flag is set in the car that they just have to check for to determine if they're really at fault for what you're claiming or not.