These are exciting times for observers of the automobile industry … and for a small percentage of investors in it. The Toyota Prius has become the poster child of the hybrid car movement, leading a growing range of hybrid offerings–including the massive Cadillac Escalade– from nearly every manufacturer. Pure electric cars are just beginning to emerge, with the Chevy Volt and Nissan Leaf targeting the mass market and Tesla aiming higher. And as these technologies improve and gasoline and diesel-burning engines are gradually displaced from our roads, the result will be lower pollution, better health and lower oil prices,...