This is no different than some apps on phones. If somebody really wants to play games while driving, and if they're going to lie in order to do so, they could just use a tablet. Granted, this setup makes it easier and therefore increases the chances people will abuse it, but I don't really think it's the core issue. Also, what about the distraction it would be to the driver if it really was a passenger playing, having that right there in front of them, especially at night? Maybe they could use polarization of the screen to make it invisible to the driver when the car is in motion and a game or video is on it. Still wouldn't solve the issue of them using a separate tablet, but nothing will.