Clayton joined GM as a co-op student with the Moraine, Ohio, assembly plant in 1983. She held various production, engineering and maintenance assignments at the plant until 1992, when she became its assistant superintendent of production. In 1994, she was promoted to area manager of body operations at Fort Wayne, Ind., and in 1995 she was named area manager of general assembly. She was appointed assistant plant manager at Fort Wayne in 1997, and named plant manager at GM's Oshawa, Ontario, truck assembly plant in 1999.
She played an integral role in the launch of the original and redesigned midsize Chevrolet Blazer, GMC Jimmy and Oldsmobile Bravada sport utility vehicles, as well as the Chevrolet and GMC full-size pickup trucks.
Clayton, 37, earned a bachelor's degree in general engineering from Wright State University in 1986, and a master's degree in engineering management from the University of Dayton in 1992. She completed the London Business School Executive Program in 1997.