I think you are making false assumptions. One can not drive any car without using the vehicle interface on an almost constant basis, including the Tesla. Since the Tesla only has a touchscreen for interfacing with the vast majority of the vehicle's functions, you are therefore using it constantly - that is my argument. But maybe you use cars differently than myself and those I've surveyed, e.g. music browsing, imperfect automated climate control settings, navigation, insane/ludicrous mode, apps, etc.