If people bought items with their head, the 7 MPG Hummer would never have become a craze. Elon Musk knew that people buy with their heart and being environmentally friendly is not enough for Teslas to become a best seller. The exterior that based off the look of a sports car/luxury sedan; the interior that is the most spacious of any on the market; and the sleek, user friendly touch screen control panel in the front have all made sustainable driving desirable.