DETROIT — After an impressive first day at the auto industry’s biggest trade show, General Motors Chief Executive Rick Wagoner can afford a little bravado. Speaking with reporters here in Detroit Sunday, Wagoner said that this year he expects the world’s largest automaker to sell more vehicles this year domestically than the 3 million it sold in 2006. The prediction seems like a tall order, given that U.S. vehicle sales are projected to be flat this year and domestic automakers have been losing share to Asian rivals led by Toyota and Honda. But the struggling U.S. automaker has earned some bragging rights. On the first day of the 2007 North American International Auto Show, GM swept the car and truck of the year honors and wowed critics with its Chevrolet Volt sedan concept, which boasts a battery-powered electric motor that will be able to run for up to 40 city miles on a single charge. The Volt, which is years away from market and will require significant advances in battery technology, is designed to run on little or no gasoline, unlike hybrids currently on the market. That will be music to the ears of environmentalists and […]