The Detroit Auto Show used to be all about size, speed, style and America's domination of the world market. This year even China's in on the action, marketing strategies you might call unorthodox, while more familiar players push plug-in hybrids, clean diesel and cars that run on industrial waste. Toyota is competing with GM to go green, but has to admit that the auto industry will always be bad for the environment. What's next for American drivers? Can the world sustain the expanding automobile economy?