No one has ever accused the auto industry of rushing madly into the future. For every superclean electro-diesel-charged concept at an event like Detroit's North American International Auto Show, there are approximately 15 Hemis. Still, the show floor always contains plenty of clues about how technology is changing the way we drive. And based on what we saw this week in Detroit, we can be sure that plug-in cars are still very much alive, self-driving vehicles are inevitable, and a German luxury sedan will soon break the sound barrier. Here are nine highlights. And for more coverage of the Detroit auto show, go here.