When K.I.T.T. and Michael visit the junkyard, the compactor is crushing the same two cars that it was crushing in the beginning of the movie.
When the villains spot Julie "driving" through the park, K.I.T.T. is always moving slowly; he never stops or parks. Yet when the car chase is about to begin ("Pedal to the metal, K.I.T.T.!"), K.I.T.T.'s lighted dashboard powers up as if he'd been turned off, and his gearshift moves from "P" to "D".
One of the suspects is identified as "David Dudley", yet K.I.T.T.'s dashboard display lists his name as "Larry B. Dudley".
The Black Porsche that KITT chases, is visible in the mall parking lot before it is introduced in the story, while Michael is looking for the proper parking space.
When K.I.T.T., Michael and Julie enter the breakers yard and Michael asks K.I.T.T. if Gastner is around, the usual stock shot of K.I.T.T.'s nose scanner is used, but the reflections in the hood show that K.I.T.T. is stationary in that shot, despite the fact that the car is in motion at the time.
The blind girl wears a watch with glass (it reflects in one of the scenes) as is usual for most of us, but a blind person has a watch where you can feel the time.
When KITT flies out of the car compactor, a close up shot of his undercarriage is shown. But the aerial shots show that the undercarriage is smooth (i.e. it's not a real car, but something built to look like one)
The same classic white Volkswagen Beetle with a purple stripe is visible in multiple unrelated scenes, including the mall parking lot, the hospital parking lot, and in traffic during the high speed chase.
In the final breakers yard scene when Michael and K.I.T.T. move to intercept Gastner in his car, a very large dent is visible on the rear right-hand panel of K.I.T.T.'s bodywork.
Kitt doesn't allow just anyone into the car. Michael was knocked unconscious and Kitt's door was opened by some men who then put Michael into the car. What's more, Kitts steering wheel was a small round steering wheel.
At about 9:20 a big dent in KITT's left front fender is visible.
When Michael slams on the brakes to avoid hitting the truck while pursuing the shooters of John, the camera crew are reflected in KITT's door.
Guide dogs are well trained to never bark. Sugar (the guide dog) barks a lot without being corrected by Julie.
KITT misquotes Shakespeare. In reciting the most famous line from "Richard III" he says "now is the winter of my discontent" instead of the correct line, "now is the winter of our discontent."
The Foundation goes to great lengths to preserve the informant's anonymity--understandably since his employer has tried to kill him--but then Michael blows his cover by declaring he works for the Foundation and chasing the informant in front of his coworkers.
When Michael enters the shop a woman pushing a baby cart approaches the same door. He walks in and ignores the woman instead of holding it open for and her baby.