Windows are definitively required by law in many countries, as it allows other drivers (in other cars) to see through a vehicle to anticipate for what's happeni

Windows are definitively required by law in many countries, as it allows other drivers (in other cars) to see through a vehicle to anticipate for what's happening in front of it. In my country (the Netherlands) even tinted windows are prohibited for this reason. Also, for most passengers in a driverless car, windows would be important. As many humans (including myself) get motion sickness if they have no reference of the outside world.