The damage to K.I.T.T.'s hood following the altercation with Goliath does not match the damage at the end of Part 1. In fact the hood doesn't match either, even without the damage.
Shortly after the "Goliath" truck starts firing its missiles, you can clearly see that some of the missile tubes are empty because the missiles that had been in them have been ejected. But then in a later shot of the truck, all the missile tubes are full again.
Mr. Garthe Knight leaves the door to Goliath open when he leaves the truck during the missile heist. When going back into the truck, he has to open the door again.
As Elizabeth Knight forces Michael Knight to watch Goliath's assault on Red Bluff on a small television set, the camera angle suddenly switches to a shot inside the military base showing Goliath bursting through the doors. There is no way they would have access to that vantage point.
Just after KITT exclaims "Look out, Michael, there's a mountain!" as they swerve about in the desert, the wheels kicking up dust, the tyres squeal as if they're on a tarred road.
The map in the wall in the General office is wrong, for instance, Mongolia includes areas of China, reaching Korea and the Yellow Sea.