DETROIT, Sept. 10 (UPI) -- U.S. automaker General Motors Co. said Thursday it would give dissatisfied customers a full refund on cars up to 60 days after the purchase date.

The move, perhaps a first for the industry, is both a gamble and a test of confidence in its products. New cars traditionally and notoriously lose value the moment they are driven out of the dealer's showroom.

The new guarantee is part of a brash, "May the Best Car Win" promotion campaign. In new GM television advertisements, GM Chairman Edward Whitacre Jr. tells viewers, "we're putting our money were our mouth is," The New York Times reported.

The refund offer covers 2009 and 2010 model year Chevrolet, Buick, GMC and Cadillac models, except medium duty trucks, GM said. Customers can return one vehicle per household, if driven less than 4,000 miles. The offer includes cars purchased between Sept. 14 and Nov. 30.