General Motors on Tuesday announced, "Zero to Sixty," which it said is the most sweeping retail marketing programme in its history. Effective April 1 through April 30, GM is offering interest-free financing for 60 months on the purchase of any new 2003 GM model Cadillac, Chevrolet, Saab, Saturn, Pontiac, Oldsmobile, GMC and Buick. Additionally, GM is offering very competitive cash rebates of up to $3,000 on most models.