It started with a letter from an 11-year-old with one simple question: how can I design cars?

Ed Welburn's career at GM has spanned more than four decades and will come to an end July 1st 2016 the designer announced today. He is to be succeeded by Michael Simcoe who currently heads up GM's international design ops.

"GM Design is among the most respected and sought-after organizations in the industry because of Ed's leadership. He nurtured a creative, inclusive and customer-focused culture among our designers that has strengthened our global brands," said Mary Barra, GM chairman and CEO.

Welburn is only the sixth design chief in the General's colorful 108-year-history; following Harley Earl, Bill Mitchell, Irving Rybicki, Chuck Jordan, and Wayne Cherry.

When GM named Welburn vice president of GM North America design in 2003 they made him the first African American to hold a lead design position for any automaker. In 2005 the company named him vice president of global design--currently he oversees all of GM Design's 2,500 global employees.

Under Welburn, GM has built a network of 10 design centers in seven countries-- the U.S., Germany, South Korea, China, Australia, Brazil and India-- who collaborate on the design progression of every General Motors concept and production vehicles world over.

Mark Reuss, executive vice president, Global Product Development and Global Purchasing and Supply Chain, praised Welburn's creativity and leadership. "Ed's team turns out one award-winning product after another … and his strong bench will keep GM Design on top for years to come."

The man replacing Welburn is no stranger to success either. Simcoe has been in his current role overseeing overseeing GM's production and advanced studios in Korea, Australia and India since 2014.

Simcoe cut his teeth with Holden back in the 80's and 90's before becoming Director of Design for GM Asia Pacific in '95 and then moving up to become executive director of Asia Pacific Design in 2003; leading development of the new GM Korea design operations under Welburn.

In 2004 GM named Simcoe as executive director of North American Exterior Design--he was responsible for the GMC Terrain, Buick LaCrosse, Chevrolet Camaro and Equinox and Cadillac CTS. More recently, he led the team responsible for the Buick Avenir Concept

"Given his deep global experience and passion for breakthrough design, Michael is the right person to lead GM Global Design," said Reuss. "He is known for his ability to take diverse ideas and mold them into great products that surprise and delight our customers."

Simcoe will transition into the top job on May 1st 2016.