In poor weather conditions a rear windshield wiper provides clear vision through your rear view mirror’s line of sight. As a bonus, it usually allows for the incorporation of a washer-fluid dispenser that can improve vision in dry conditions, too. Rear wipers come standard on SUVs and many hatchbacks, but why don’t all cars have one?
Is a Rear Windshield Wiper Even Necessary?
Many opinions exist regarding the absence of rear windshield wipers on sedans. Some claim that because of the aerodynamics of a sedan, it doesn’t require one: Windshear alone does a fine job of driving water, snow and debris from the surface of the glass.
Others point to the body style: The length of the trunk compartment acts as a buffer between the wheel spray and the window, preventing it from settling on the glass.
Another opinion returns to aerodynamics, suggesting that air movement over the top of a sedan would lift the wiper from the surface of the glass, making it useless.
Rear Windshield Wiper Manufacturing Considerations
There are all sorts of possible reasons that car makers might choose to leave off a rear windshield wiper. Some that top the list: Lack of space to conceal a rear windshield wiper motor and washer-fluid reservoir, the added cost of the system, weight reduction considerations (to meet fuel-efficiency standards), increased drag (which disrupts aerodynamics, and once again, fuel efficiency) and cosmetic appeal.
Rear Windshield Wiper: The Final Word
The most satisfying answer in the end? Because the car designer decided not to put one there. Exactly why they made that decision could well have to do with any of the speculations above, as determined by their unique set of traditions, values and sensibilities.