This was the very first time Mattel offered a Hot Wheels Club and there were 3 mail in only chrome cars. They Club Kit Cars are Heavy Chevy , Boss Hoss Silver Special , King Kuda . Why the others never got a special name? Collector's have just called them " The Club Kit Cars" makes sence. Spectraflame painted Heavy Chevy and King Kuda cars were already part of the 1970 lineup, and The Boss Hoss was later released as a main line car in 1971. All three had black-stripes and assorted numbers on the door. Came with either black or white interior.