When Max and Jarrett are approaching Michael and RC for the final fight, they suddenly switch places.
The 'safe' that donald crane opens in his office is just a cupboard. When he opens the door, it is just a few millimetres thick, and has no locking mechanism whatsoever.
(at around 29 mins) A driver's hands can clearly be seen spinning K.I.T.T.'s wheel when the car is supposed to be driving itself.
The safe that has a silent alarm has a rotating beacon inside. It does not make sense to have a silent alarm but have an indication that the alarm has been activated.