You do know that refining oil needs loads of power too? Refineries are generally build near power stations. Electric cars can use renewable power too. Even if you cover a car in solar panels it is fairly limited in what benefit it can get. The weight of the panels may be an issue too. Cars have been built with panels, but not sure any are in production. Just building any car is a polluting process, but we do need to really reduce pollution in cities. Less cars is the real answer.