Why would you wonder? Do you think that electric cars have special, electrically conductive tires? I suppose it’s probably a good idea to unplug your Tesla along with your TV set, your microwave etc.
it is safe in a car not because the tires are an insulator, in fact at those high voltages they conduct quite well. The reason cars are safe is because the body acts like at
faradays cage, just like high tension powers are washed by a person from a helicopter wearing a metal mesh suit, it acts as faradays cage.
The tires are not the reason a car is safe during a thunderstorm. That’s a misconception.