Continuity mistake: When Vic picks Tad up at his camp, we see Tad dip his finger in paint and begin finger painting. He then sees his dad and runs to him and gives him a hug and there is no paint on either of his hands or his dad's suit. (00:29:50)
Visible crew/equipment: There is a shadow of a crewmember passing over the fridge, as the camera pans along and follows Donna into the kitchen, in the scene where she goes to the sink for a glass of water, before being startled by Steve. (00:30:30)
Visible crew/equipment: When Cujo gets into the vehicle and is fighting with the woman, we see a shot behind the dog. The shadows of a boom mic and film equipment are blatantly visible.
Factual error: The car is equipped with shatter-resistant glass yet Cujo manages to break through - even rabid, this should not be possible.
Visible crew/equipment: As the car is breaking down a second time, the camera is moving around the driver's side. It is visible in the glass, bottom left.
Visible crew/equipment: When Vic is about to leave Donna and Tad, aftering finding out about the affair Donna had, in a side view of Vic in the car, the boom mic is clearly reflected in shiny back of the side mirror for about twenty seconds. (00:37:50)
Answer: Not really. Rabies has a wide range of behavioural symptoms, and it's rare for a rabid dog to display what's called "furious rabies," whereby they become more aggressive. And even then, they wouldn't become single-mindedly determined to terrorise two people in a car. It's much more common for a rabid dog to get slower/lethargic as paralysis sets in, eventually leading to coma and death. You can find more info here: https://vcahospitals.com/know-your-pet/rabies-in-dogs.