Slammin' Sammy's Stunt Show Spectacular - S1-E5
Deliberate mistake: Watch the end of the test run for Michael and KITT. Michael was using the KITT steering wheel, but then he gets out of the car and it switches to a performance steering wheel instead.
Slammin' Sammy's Stunt Show Spectacular - S1-E5
Revealing mistake: As KITT goes into ski Mode to show Sammy what he can do, the stunt driver is obvious, and there's a bar mounted on the door just back from the driver's mirror for the driver to hold on to. Also, the regular steering wheel is easily spotted through the windshield.
Slammin' Sammy's Stunt Show Spectacular - S1-E5
Other mistake: At the end of his "audition", as Michael approaches the pit area, it's his stunt double with a bad wig.
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"