Chevrolet will use next month's World Series to barrage ads for the admission of the Volt constituent amalgam sedan, General Motors Co.'s business arch Joel Ewanick said today. The ads will be allotment of a ample attack that Chevrolet will admit during Major League Baseball's abatement archetypal and run throughout autumn, said Ewanick, who batten on the sidelines of the Rainbow PUSH auto acme in Detroit.