1970 was another great year for Hot Wheels. This was also the year that Sizzlers appeared. Howard Rees, who worked with Ira Gilford, was tired of designing cars. He wanted to work on the Major Matt Mason action figure toy line-up. Rees had a good friend by the name of Larry Wood. They had worked together at Ford designing cars. When Wood found out about Hot Wheels at a party Rees was holding, Rees offered Wood the job of designing Hot Wheels. Wood agreed, and by the end of the week, Larry Wood was working at Mattel. His first design would be the Tri-Baby. After 36 years, Larry still works for Hot Wheels.
Another designer, Paul Tam, joined Larry and Ira. Paul's first design for Hot Wheels was the Whip Creamer. Tam continued to work for Mattel until 1973. Among the many futuristic designs Tam thought up for Hot Wheels, some of the collector's favorites include Evil Weevil (a Volkswagen with two engines), Open Fire (an AMC Gremlin with six wheels), Six Shooter (another six wheeled car), and the rare Double Header (co-designed with Larry Wood).
1972 and 1973 marked a slump for Hot Wheels; few new castings were produced, and in 1973 most cars changed from Mattel's in house "Spectraflame™" colors to less-shiny solid enamel colors, which mainline Hot Wheels cars still use today. Due to low sales, and the fact that many of the castings were not re-used in later years, the 1972-3 models are known to be very collectible.
In 1974, Hot Wheels began using the slogan "Flying Colors", and added flashy decals and tampo-printed paint designs, which helped revitalize sales. As with the low-friction wheels in 1968, this innovation was revolutionary in the industry, and — although far less effective in terms of sales impact than in 1968 — was copied by the competition, who did not want to be outmaneuvered again by Mattel product strategists.
In 1977, the Redline Wheel was phased out, with the red lines being erased from the wheels. This cut costs, but also reflected that the red lines popularized during the era of muscle cars and Polyglas tires were no longer current.