Senior Pentagon acquisition officials are scrambling to establish a sound legal footing for a quick-moving armored vehicle program that sprouted last fall from an urgent request from Marines in Iraq into a $7 billion effort to procure nearly 7,000 vehicles that offer enhanced protection against roadside bombs. Armored vehicle makers are jockeying for a chunk of the Mine Resistant Ambush Protected (MRAP) program, which the Bush administration, the Army and the Marine Corps are touting as one of the U.S...