TechnologyMind-BlowingHot Wheels came out in 1968 built to outrun every other toy car. Mattel handed the problem to its head of research. He had come from Raytheon, where he worked on the Sparrow and Hawk missiles. The fix was a thin music-wire axle spinning in low-friction plastic bearings. Rival Matchbox cars were still rolling on nail axles. Mattel still makes 22.5 Hot Wheels a second.2 hours ago