Chevrolet Volt was the best-selling plug-in electric vehicle in the U.S. in May, topping Toyota’s Prius Plug-in and Nissan’s all-electric LEAF. Sales of Chevrolet Volt have topped 7,000 in the first five months of 2012 — almost as many as it sold in all of 2011. General Motors Co. said it sold 1,680 Chevrolet Volt […]

