If they don't get any feedback, they might not get anything from it anymore.

You are on to something here. I have started driving a small car in the UK (Ford Fiesta) and have discovered it's a magnet for the road rage people (around 50% of drivers here).

Firstly, I never back down and will come to a complete stop if slowing down doesn't work. Secondly, I have noticed these drivers feed off any reaction and that avoiding eye contact works very effectively, even if they pull beside you to have a childish rant.