Biff Manard was actually drunk while playing Hap Ashby, and Tim Thomerson had to literally man-handle Manard because he had no idea what he was supposed to be doing or where to go.
The pro-ball tooth that Ashby spits out was Biff Manard's actual tooth. Tim Thomerson gave Manard money after the shoot to get the tooth repaired.
At the time of Trancers (1984) release, one of the marketing assistants who had just started working for Empire International Pictures was future actor Greg Kinnear, and "Trancers" was his first film that he was assigned to help promote it for the studio. Thirteen years later, when Kinnear had become a full-time actor, he would co-star with Helen Hunt in As Good as It Gets (1997), for which Hunt won the Best Actress Oscar and Kinnear was nominated for the Best Supporting Actor Oscar.
Jack Deth's car is a 1955 Mercury Montclair that was heavily modified by Gene Winfield, who built the spinners and full-sized cars for Blade Runner (1982).