I don't think there's any doubt the young lady could have handled it better. She was clearly trying to goad the people in the car, but who knows what was said in the leadup to her filming.
But in any event, my god be an adult and be a decent human. If you don't like what she's saying roll your window up and ignore her. It's not that hard to just not engage. And then to not only hurl a racial slur at her, but doubling it down with "you don't belong here" is truly awful.
No doubt everyone probably could have handled this better, but one party took it well beyond into something despicable.