Could not get past all the nonsense....bigfoot is more plausible

No way someone like that lets a perfect stranger drive them to a hospital for what is clearly a superficial skin wound......especially when he is in front of his own house and he has his own car.........knowingly leaves his keys/wallet/cellphone inside his unlocked house........and he knows this guy has car problems

The girlfriend doesn't seem too concerned that her car is getting rammed.

Also this stranger murders the truckdriver with the girlfriends car and the girlfriend nor him are very much concerned about the murderering psycho in their presence nor him with them in the car.

The girlfriend isn't too concerned about

1) Missing cellphone
2) Damaged car
3) Murder by a psycho
4) Getting in a car with a murdering psycho...that did not FORCE them into the car.

Still they are willing to get into the car with the psycho and 'find help' with zero concern for themselves.

Not until the girl gets pistol-whipped many minutes later......she is kinda concerned.