Are the DMV records public in many states? It seems like you could feed a corpus of video into a license plate scanning algorithm and lookup make/model from DMV records, if available. Presumably, that would be more accurate than trying to recognize the vehicle from appearance (either manually or using machine learning).
Movies are often shot on private lots. There is no requirement that a vehicle actually be registered and be using a real valid license plate unless it is driven on public roads. (at least in the US)
I would be curious if that database is public, though.
And if it is computer vision, how did they get the footage?