You’d never drive around Oceanside with a broken windshield, because you know that is not only dangerous but also illegal. What about the other windows in your car, though? It’s easy to forget, but all of your windows are there for a reason and therefore just as important.

What about those little side windows, next to your big windows? Have you given much thought to these? Many people have not. Vent glass, also called quarter glass, is important to the structural integrity of your vehicle as well as your line of vision. Let’s dig deeper into this.

Table of Contents

  • Understanding the Purpose of Vent Glass
  • Why Is It Called Vent Glass?
  • Professional Vent Glass Replacement

Understanding the Purpose of Vent Glass

Vent Glass on TruckThe term “vent glass” is the professional word used to describe the small glass window that is a side-facing window on a vehicle. It is significantly smaller than the standard passenger windows.  In many vehicle styles, it serves as an extension of the passenger window either above the rear wheel or next to the side-view mirrors.


These windows greatly enhance the driver’s visibility of the surrounding area. They allow the driver to view an area that would typically be a “blind spot.” When a car has these windows in the front, they allow the driver to have increased visibility to their side and in front of them.

Why Is It Called Vent Glass?

Vent glass is found in rear and front windows, and sometimes in front of the front doors. As with many things in life, the name of the item no longer makes a whole lot of sense because it doesn’t do the function it once did. Consider why the storage area in the front passenger side of your car is called the glove compartment!

They were found on vehicles that did not have air conditioning. The role of these vent glass windows was to help keep the driver and passenger seats of the car at a comfortable temperature.

Your front windshield still has a very important function, even in the newest cars. In today’s modern vehicles, the purpose of side vent windows is cosmetic. In some models, their function is to make rear door glasses able to roll down farther than they would without the vent glass. Many drivers don’t realize it, but the rear wheel takes up part of the corner of the door. 

Professional Vent Glass Replacement

Professional Vent Glass ReplacementThese small but important glass panels are made from the same tempered glass that your windshield and passenger windows are made of. For this reason, if there is any damage to the vent glass, it should be addressed immediately.

If the glass itself breaks, you need a full replacement. Some vehicle owners are under the impression that since the vent glass is the smallest piece of glass on their vehicle, it is the least important to replace. This is not true! 

Just like your damaged windshield, side windows require replacement when they’re broken. North Coast Auto Glass offers professional vent glass replacement services.