Revealing mistake: When KITT is in the valet carpark, he pushes the cars in front of him forwards. It is very obvious they have attached rubber protectors to the bumpers to prevent damage. Also, when KITT is driving by himself 10 seconds later, you can see the stunt man's hands driving the car.
Revealing mistake: Watch the scene where Michael fights two guys for a purse. Michael calls KITT for help. When KITT jumps off a cliff, an old vehicle is the one that jumps off the cliff instead.
Answer: KITT didn't choose to go off the cliff in Goliath Returns, it just happened as he tried to avoid Goliath. Just 'cus it happened, doesn't mean It's gonna cure his fear of "flying"