David Hasselhoff was injured whilst filming the close-up of Michael's slide down the elevator, and required "emergency surgery" on his posterior. He remarked to TV Guide at the time, "I'm on my feet and walking around now but I'm not sitting pretty."
The cameo appearances weren't scripted with Jerry Quarry, Don King et al. necessarily in mind. Quarry's part is "Jerry Red", and Don King was written as "PR Man." Carlos Palomino and Danny Lopez were added in later stages.
The rerun of this episode was the last ever Knight Rider to be shown in its prime-time slot on NBC on August 8th, 1986.
As scripted in the early drafts, Michael proceeds to drop-kick Davis after the promoter tells him he has a bad heart. This admittedly bad decision was rectified in later drafts.
The dam where Michael met with Spiderman was also used in the season two episode, Knight Rider: Knightmares (1983).