Though carmakers are painfully aware that people living in big cities are less likely to own a car than in less densely populated areas, where public transit isn’t as convenient of an option, that isn’t keeping them from trying to get a foothold one way or another in those markets. At some point or another, even city dwellers find themselves in need of a car. To that end, General Motors is testing a car-sharing program in Manhattan, to rival services like Uber and Zipcar. [More]