So... does this mean I could sue Ford if someone modified a Ford car with a nitrous oxide booster? Could Ford sue the modifier for ruining the reputation of Ford when they crashed a modified Ford car? Will the state sue Ford for allowing such modifications, commonly used in street races? Can there be a civil suit against ford for anyone harmed by such modification?
To me, all those questions has a clear answer, and that answer is No. It also has a historical proof, as there hasn't been any lawsuits against Ford for failing to prevent such modifications. If the owner of a car modify their own car, then that person is fully responsible of any consequences of that action.
"It is the socially responsible thing for Tesla to make guarantees about their car software performance and prevent tampering in order to keep our streets safe."
"It's my product, I own the car; I have the right to tinker with all of it."
I observe that we constantly have this same debate: can we be responsible and take care of ourselves or do we need some ruling class to take care of us and micromanage our decisions for us? Or philosophically, can mankind be perfected through laws?
Half-measures and exceptions in the self-determination debate always strike me as lacking wisdom. Culturally, we should be strongly predisposed one way or the other.
"We're allowing you to unlock your bootloader, but if you do, you're voiding your warranty."
Similarly car makers could say as soon as the user unlocks the car's systems for modification, the company is no longer responsible for any accident that might happen.
It seems like a rather good compromise to me.
Check out the Fast and Furious movies if you're interested.