"Tubby's Drive In" was actually an A&W Root beer that was closed down. It was located (then) way out on Van Nuys Blvd. Nothing worked, no bathrooms, plumbing, grills etc. Many people sought to buy the place after the film, and convert it back into a working drive-in for a gathering place for hot rods, but it never happened.
Duke's yellow '57 Chevy was "Popular Hot Rodding" magazine's famous "Project X" test car. The transmission was damaged during filming (you can see the smoke roll over the top of the car when the engine gets hurt during the race with the Cobra).
According to the 'Wikipedia' website, ''the movie built a cult-like following during the 1980s due to repeated late-night airings on HBO.''
Hollywood Knights is the first major film for Tony Danza, Michelle Pfeiffer and Robert Wuhl, who all would go on to achieve their own individual stardom.
During production, some of the film's interrelated stories grew in importance while others virtually vanished. The youthful cast was not surprised. Writer-director Floyd Mutrux had set the ground rules on the first night of principal photography. He said: "What 'works' is going to be in this picture. What doesn't, isn't. A lot of you have never been in the movies before except by buying tickets. If you're terrific, you're going to spend more time on screen than you ever imagined."