A recent voyage to El Segundo, California, brought us to the doors of the Mattel headquarters. Inside, we were given the chance to take a behind-the-scenes look at the Hot Wheels design studio, and spent some time with the head of design. We learned all about the brand's design ethos, new products and the never-ending joys of being a toy designer. Also on show was the brand's latest Car Maker product, which gives you the chance to mold custom Hot Wheels at home. Pick up your own Car Maker online from Mattel for $50.