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GoogleQuarter glass and vent glass are the small side windows that sit apart from the main door windows. Quarter glass usually refers to a small pane near the rear of the vehicle, behind the rear door or beside the rear pillar, and it is usually fixed. Vent glass usually refers to a small pane at the front of a door, near the side mirror, and on older cars it often opened to let air in. The names overlap from one shop or manufacturer to another, so the location on the vehicle matters more than the word. These panes break mostly from impacts, such as a thrown stone, a break-in or a collision.
Because they are small, quarter and vent windows are often a target in break-ins and easy to overlook when ordering parts. This guide is written by Mavi Auto Glass, a locally owned, 100% mobile auto glass company based in Roseville that replaces quarter and vent glass on cars, SUVs, pickups and vans across Sacramento, Roseville, Citrus Heights, Elk Grove and the rest of Greater Sacramento. It explains how to tell the two apart, why they break and what to send for the right part.
What is the difference between quarter glass and vent glass?
The difference is mainly where the pane sits and whether it opens. The table shows how the terms are commonly used.
| Name | Where it usually sits | Does it open? |
|---|---|---|
| Rear quarter glass | Behind the rear doors, beside the rear pillar or at the rear corners of SUVs and wagons | Usually fixed |
| Rear door quarter glass | A small fixed section inside the rear door, next to the main window | Usually fixed |
| Front vent glass | A small pane at the front of the front door, near the side mirror | Usually fixed on newer vehicles |
| Opening vent window | Front of the door, on some older vehicles | Opens to let air in |
Some vans and SUVs also have rear side windows that pop open, and they may be called quarter or vent windows depending on the manufacturer. When in doubt, describe the window by its position on the vehicle.
Why do quarter and vent windows break?
Mostly from a direct impact. A stone thrown by another vehicle, an object hitting the side of the car, a collision or a break-in can all break these panes. Many side windows are made of tempered glass, which breaks into many small pieces instead of cracking, so a broken quarter glass usually leaves an open hole rather than a cracked pane.
In break-ins, a small quarter or vent pane can be a quicker way into the car than a main window. If that happened to your vehicle, see how to cover a broken car window until it is replaced and whether insurance covers a window broken in a break-in.
Can a broken quarter glass be repaired?
Usually not. When a tempered quarter or vent pane breaks, it shatters, and the fix is a replacement. Some vehicles use laminated glass in side positions, which cracks instead of shattering, but a cracked side pane is also normally replaced rather than repaired.
The replacement is done at your home, workplace or another suitable location in most cases. The broken glass is cleared from the frame and the cabin, the new pane is installed and the area is cleaned before the technician leaves. Learn more on the quarter and vent glass replacement page.
What should you send to get the right quarter or vent glass?
Send the details that pinpoint the exact pane, since small side windows differ by body style, trim and side of the car. You can gather them in 4 steps.
- Identify the position: note front or rear, and driver or passenger side.
- Take two photos: one close up of the opening and one of the whole side of the car showing where it sits.
- Add the vehicle details: year, make, model and VIN, plus the cab type for a pickup.
- Mention any other damage: door glass or back glass broken in the same incident can be quoted together.
If the code in the corner of a surviving pane is readable, a photo of it helps too. The VIN and photos are what let the shop confirm the part before the visit.
Protecting the car until the quarter glass is replaced
Even a small opening lets in rain, dust and a hand, so act before the appointment.
- Photograph the damage before cleaning, especially after a break-in
- Remove loose pieces from the frame with thick gloves
- Vacuum the glass from the seats and floor
- Tape clear, heavy plastic over the opening
- Take valuables out of the car and park in a secure spot
Getting ready for a quarter or vent glass replacement
Describe the window by its position, send the photos and the VIN, and mention any other glass broken at the same time. Keep the opening covered and the car secured until the visit, and if you plan to use insurance, have the police report number and the claim number ready. Qualifying auto glass installations carry a lifetime workmanship warranty against installation-related leaks and wind noise.
