George Soulakis, Howard Rees

George Soulakis — George Soulakis Jr. was a Mattel designer and engineer from 1968 to 2000 and the main engineer and designer behind the Sizzlers line. In 1972 he suggested using the tampo printing process to apply graphics to the cars; Mattel invested more than US$100,000 in equipment, and the technique has been used on Hot Wheels cars ever since. He retired in 2000 and died in 2025.

Howard Rees — Howard K. Rees worked at Mattel from 1969 to 1975. Before that, he had accepted a position at Ford of Europe. He left the Hot Wheels design team in 1971 to design the Major Matt Mason action figures, and recommended his friend Larry Wood for the opening. He left Mattel in 1975 and became a painter, which he still is.