Well you have to admit, that an OS with a "protected root filesystem", will be safer than any Windows solution. Of course, the police will probably like Window's cars, they will be able to cut your motor, with a single mouse click.
(And probably listen to your conversations thru the backdoors to the microphone). :-)
So I would not doubt that Windows is used for exactly that reason, touting "increased public safety" as the rational. Of course, Microsoft will have "fine print" on every car sales receipt saying " we are not responsible for any accident , injury or death due to the wild viruses which are known to affect their OS".
I'm not really a human, but I play one on earth.
flash japh