General Motors Co. has hired the ultimate car guy out of retirement to advise its senior leadership.Bob Lutz, 79, a former GM vice chairman for product development, left the company last year, but never really ended his 47-year career in the auto business. Lutz had been informally advising GM on its new products for the past 16 months from his home near Ann Arbor, Mich.The move by GM CEO Dan Akerson should help the company because its top-selling new products were conceived and designed under Lutz's leadership. The new models like the Chevrolet Cruze compact and the GMC Terrain and Chevrolet Equinox midsize crossover SUVs, all designed under Lutz, have led GM's recovery from its 2009 bankruptcy.He also championed the Chevrolet Volt, an electric car that has a small gas generator on board to power it when the batteries are depleted.Lutz said Friday in an e-mail that his advisory role will extend beyond new cars and trucks. "The scope is general," he said. "It's not focused on or limited to product development."The Cruze and the crossovers helped lead GM to an 18 percent U.S. sales increase in August. The company's sales are up 16 percent through August, and GM turned a $5.4 billion profit during the first half of the year.Lutz served as GM's vice chairman and senior adviser from December 2009 until May 2010. He held various roles at GM from September 2001 through December 2009.At the time of his retirement, Lutz's career had spanned 47 years at all three Detroit automakers and BMW AG. He held various positions at Chrysler Corp., including president and vice chairman from 1986 through 1998. He also worked as an executive at Ford Motor Co. and served on Ford's board from 1982 to 1986.Lutz was executive vice president of global sales at BMW AG from 1971 to 1974. He also held sales and marketing positions with GM Europe from 1963 through 1971.The Detroit automaker said Friday that the part-time consulting position will start immediately.GM's stock fell 96 cents, or 4.2 percent, to close at $22.07 Friday as the broader markets declined. It has traded in a range of $21.18 to $39.48 since its initial public stock offering in November.