The Rip Racers set of Happy Meal™ premiums consists of four plastic cars measuring approximately 6cm.
Included with each car was a ripcord to propel the car and stickers of the McD character:

Ronald McDonald™ - red Formular 1 Racing Car with yellow ripcord.
Birdie™ - yellow Rally Car with pink ripcord.
Grimace™ - purple Formular 1 Racing Car with green ripcord.
Hamburglar™ - green Rally Car with orange ripcord.