But he or she won't be able to watch the online trailer. When the Model S is moving, its screen can't display videos, which NHTSA's vehicle safety standards prohibit within the driver's view. NHTSA's distraction guidelines, which explicitly prohibit Web browsing in a moving car, will challenge the iconoclastic automaker. On other regulatory questions, Tesla founder Elon Musk has taken the stance that his company will do what the law requires and that, beyond that, it will do what it considers best. Since the NHTSA guidelines are essentially voluntary, this one could become a standoff.