In a move to shore up public confidence following its stint in bankruptcy court, General Motors on Tuesday unveiled its 2-year product plan for the four core brands: Chevrolet, Cadillac, Buick and GM. Included in the Chevrolet news is that production of the C7 Corvette will start in April 2012 for the 2013 model year. GM also added that the Corvette will maintain the front-engine layout that has defined the sports car for 57 years.