All three of the main stars, Jackie Chan, Yuen Biao, and Sammo Hung, all were seen in Bruce Lee's Enter the Dragon. (Jackie plays a guard who gets beaten by Bruce in the underground hideout, Sammo plays Bruce's opponent in the opening of the film, and Yuen plays a tournament fighter).
The reason that the film is titled "Wheels on Meals" instead of "Meals on Wheels" is because of superstition. Golden Harvest had produced two films beginning with "M", Megaforce (1982) and a film titled Menage a Trois, both of which were major flops. So the company's executives changed the title hoping this film would avoid the same problems, which it did.
There have been many rumors as to what happened during the filming of the big fight scene with Jackie Chan and Benny Urquidez, ranging from the film makers threatening to fire Urquidez for hitting Jackie too hard or that the two actors did not get along. While they were somewhat competitive during rehearsals and filming for the fight, they respected each other and at the end of filming gave each other a big hug. (Source: 'Jackie Chan: Inside the Dragon' by Clyde Gentry
During filming, Keith Vitali accidentally kicked Jackie Chan in the throat after numerous takes for a particular fight scene. When Keith hit Jackie, he realized the danger of the situation and broke character by concern for Jackie's health. By doing this, Keith was yelled at by the entire crew as he was supposed to wait for the director to yell cut no matter what had happened in the scene.
Keith Vitali had accidentally knocked Sammo Hung (who was also the director) in the head with one of his kicks, but learning from his previous lesson with Jackie, Keith didn't break character and waited until Sammo called for a cut, which according to Keith seemed like an eternity.
The trivia item below may give away important plot points.
Sammo Hung had surprised Keith Vitali by telling him his character was going to be knocked out by a vase full of water near the end of the film. When Keith was hit by the vase, he was knocked in and out of consciousness - though still manages to creep a smile onto his face as the whole crew were apparently laughing. Keith jokingly refers to this scene being composed as revenge for Keith's earlier mishap, by kicking director Sammo Hung in the head.