Toyota unveils 2010 Prius that boasts 50 mpg

Toyota is looking to keep the Prius in its spot as the top-selling hybrid in the U.S. with the next generation of the iconic fuel-sipper.

The highly anticipated 2010 Prius being unveiled Monday at the North American International Auto Show in Detroit gets an average of 50 miles to the gallon (4.7 liters per 100 kilometers). That's a 4 mpg improvement over the current model, which already is the most …