Our protagonist is a sex crazed young man who is convinced that the only way he can have sex is if he has a car, so he goes to a dealership to try several models, only to be treated like an idiot by the dealer, who only sells him overpriced crap. At least that’s what I get from the movie.
The dealer hits the same child in the head two times in the movie, both times when the dealer finds out the client is so gullible he’ll pay anything for a status symbol so he can finally have sex, both times with the child’s parents present.
Is this a trope in Japan? Not the buy a status symbol to have x, but hitting a child in the head.
Hitting inferiors in the head (especially for doing something foolish) is certainly a common trope in Japanese comedy.
It’s been a couple of decades since I lived in Japan, but I don’t know if they have experienced the same campaign against childhood violence that we have in North America. A few years ago, corporal punishment was made explicitly illegal both at schools and in the home. I’m not sure how much it has changed.