Why do they make keyboards that can type hate crime? Why do they make cameras that can shoot child porn? This is possibly the worst question I've seen in this site.
There was an interesting Radiolab recently where they talked about how the Chinese IMEs are shaping what people say and can say. It’s a genuine fear that such control could happen.
Your answer is wrong and insulting, Since you probably know most new cars have optional speed limit and GPS then it is very logical to ask why not make them opt-out then opt-in.
Now you could attempt to give a fair answer why you think this is hard to implement correctly or why is a bad idea.
Also we could theoretically install something that can detect if the driver is tired,drunk or not paying attention. There is no requirement that police or government must be involved , maybe in some countries you can implement and solve this with free market , insurance and all that good capitalistic/freedom stuff.