Automotive vent windows, small hinged glass panels in the front doors, were used for directing airflow before A/C, but were discontinued due to the rise of standard air conditioning, aerodynamics, safety concerns (pedestrian impact/side airbags), improved door sealing, and manufacturing costs, leading to smoother, sealed designs with better fuel efficiency and noise control.

Description

Function: Hinged triangular glass (quarter glass) in the front doors that could be angled outward to scoop outside air into the cabin, providing ventilation and helping to defog windows.

Mechanism: Operated by a small crank or latch, allowing them to catch wind and direct it inside, replacing the need to roll down the main window.

Common Era: A staple in cars from the 1960s, 70s, and early 80s, often removed in the mid-80s.

Reasons for Discontinuation

Air Conditioning: Became standard, making manual ventilation less necessary for cooling.

Aerodynamics & Fuel Efficiency: Open windows, especially vent windows, created drag, reducing fuel economy; modern designs prioritize smooth surfaces.

Safety: The metal post holding the vent window posed risks in side impacts, interfering with airbags and increasing injury potential; removing it allowed for stronger door structures.

Noise & Sealing: Modern door designs create tighter seals, eliminating leaks and wind noise that vent windows introduced, even when closed.

Manufacturing & Design: Simplified door designs became cheaper and more efficient to build, while aesthetic trends favored seamless glass.