In the scene where Mike, Charles and Jen are leaving the hotel, Mike has the ear piece on. When Agent Rivai confronts them, he's no longer wearing it. The scene cuts back and forth showing him from behind/her from the front wearing it and then his front not wearing it before they all walk towards KITT when he takes it off.
While side-slamming into the bad guys' SUV, KITT's left headlight smashes (you can see the metal ring fly off on impact) but it's intact for the rest of the chase. This is before KITT's repair system is turned back on.
During the final chase scene, K.I.T.T. gets his driver's side window shattered while his computer systems are still deactivated, yet in a wide-angle shot of the vehicles gathered in the road after the crash, the window is whole again. From what the story appears to say, K.I.T.T. can only "self-heal" body-damage that is done while his computer systems are in operation, so it seems doubtful that he could actually create a whole new window when there isn't one there to begin with - the destroyed window would need to be removed and a new one installed by a F.L.A.G. repair technician.
During the first chase, when KITT displays the "Knight Industries 3000 Field Tests" screen, The last item shows "High Velocity Breaking Index" where "Braking" is likely meant. Capitalization is also inconsistent throughout the display, i.e. "Nanoskin modification speed test".