[Detroit] General Motors Corp. saved nearly $4 million last year after starting a collaborative ad development system for its Latin American, Middle Eastern and African region. Before, each nation developed its own ads, mainly for Chevrolet, said Wayne Brannon, director of sales and marketing promotions for the region GM calls LAAM. Interpublic's McCann-Erickson Worldwide, Miami, coordinates strategy and creative development with each local office. Together, they pick and pre-test creative ideas in several countries before production starts. Each shop gets fee-based compensation for media buys, which is roughly 80% of LAMM's ad budget. Each country can still do local ads. The idea for a Chevrolet brand spot breaking this month came from a Canadian ad by McCann, Toronto. GM reduces production costs by bringing together different actors for separate shoots on the same location. "People were very skeptical about the concept at first," thinking different cultures would make it too difficult, said GM's Eduardo Andrade, regional director of advertising and promotion.