Sedans have a sloping roofline and a long trunk that channels airflow over the rear window.
Hatchbacks, with their steeper rear ends and shorter trunks, create a different airflow pattern.
Some argue that rear wipers disrupt the clean lines of a sedan's design. Manufacturers might choose to prioritize aesthetics in certain models
Including a rear wiper adds complexity and cost to the car. For sedans, where the wiper isn't as crucial, manufacturers might choose to omit it for cost-effectiveness.