system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do hatches and SUVs have rear windscreen wipers when Sedans rarely if ever do

What's the downside of having rear wipers on Sedan/why don't they have them?
gpt
The aerodynamics of all cars creates a bubble of air behind them causing a loop affect when it rains. This loop effect causes rain to splash back on to the rear of the vehicle.  In an SUV or other trunk less car, this means it splashes onto the rear windows. In a normal coupe or sedan, the rear is the trunk which gets hit the most. 

So essentially it just not a necessary expense to add to sedan like cars.