After Mrs. Houk gets out of the car, after narrowly missing getting hit by the train, her glasses change from the vintage batwing/cat-eye style to more modern ones (Nedra Volz's actual personal eyeglasses). This is attributed to the fact that the overnight filming of the train scenes expanded further than just one night and the continuity was missed.
During the chase sequence when they are entering the Police convention Judge Nedra Henderson can be seen wearing heels, when they leave the convention you can clearly see she is wearing tennis shoes. Later when they are entering the police station to see the Chief she is wearing heels again.
When Dana Cannon is at the front of the class posing as the instructor on the first night of traffic school, the name "Thomas Jefferson" scribbled on the blackboard behind him changes repeatedly between shots.
When Joan Pudillo loses control of her car, bowling balls go crashing through the back window. The police impound her car and when Joan's car is released from impound, the window is back to normal. As the chief drives by the long line of cars pulled over just before the end credits roll, the window is broken out again.
Mrs. Houk quickly gets out of the car after the dog licks her face, but the dog suddenly disappears.
A bowling ball would not be flung from a car--unless there is a device that catapults the bowling ball from the car, or if someone in the car threw bowling ball out.
Deputy Halik drove his car into a house, and then through a brick wall. His car would likely have some damage, especially after driving through a brick wall.
A runaway bowling ball would not knock down many people.
When the driving-school students have rigged Halik's police cruiser so that it will only go into reverse--and Halik is forced to engage in a high- speed pursuit driving backwards--it's obvious that the "rear" tires of the car are doing the steering. (That's because the Malibu's body is turned backward. Also, the small-but-noticeable gas cap is visible in the center of the front bumper.)
The bench that the person in the duck costume falls on is clearly made of foam.
You can see Mrs. Houk rub something on her face before getting into the car to attract the dog to her face.
Joan Pudillo lets go of the steering wheel and looks into her purse, which obviously made her to take her eyes off the road. And yet, her car continues to go straight. Apparently, her car is being towed.
Dana, when he gets on the bus with the plants.
When Stephanie tells Scott that she gets turned on by driving fast, her lines are dubbed.
Camera visible in the cops mirror sunglasses at 1:28:00.