why do most hatchbacks have a rear wiper but coupes and sedans don’t

Question

The angle of the glass on hatch backs varies from straight up and down to almost horizontal. They almost all have a rear wiper.

sedans and coupes can have similar glass angles, yet don’t have rear wipers.

why?

In: Engineering

Answer 1

Hatchbacks tend to lift dirt from the road, up and into the rear screen.

Coupes and sedans usually have a big gap between the end of the car and the rear screen, so the airflow coming over the vehicles is the dominant force.