A quarter window on cars and closed carriages might be a side window in the front door or else found on either side of the car, just forward of the rear window. Only certain cars have these. In some situations, fixed quarter glass might be set in the corner, also known as the C-pillar, of the car.

Quarter window is also sometimes called a quarter glass. This window may be set on hinges and is then also known as a vent window. Most often found on older vehicles on the front door, it is a small roughly triangular shaped glass in front of and separate from the main window that rolls down.

For the '87 model year, Ford switched to a much cleaner-looking rear mustang quarter windows assembly for Mustang hatchbacks and hardtops. Molded from vulcanized rubber, with the actual window glass embedded, the one-piece assembly was quite complex for a mustang quarter windows, but it served its purpose by effectively blending the roof into the rear quarter-panel. But over time, with many hours of hot sun baking the side windows, the exterior rubber deteriorated, leaving a pitted and discolored window perimeter.

Over the past 10 or so years, owners of '87-'93 Mustangs have been forced to tolerate the weathered and unsightly mustang quarter windows. Painting over the problem only makes matters worse, while an available cover-up repair kit offers temporary improvement.

Late model Restoration Supply has stepped up to the plate with the ultimate solution: brand-new '87-'93 rear quarter windows for mustangs manufactured by an original-equipment manufacturer. Priced at $599.95 per pair and available for both hatchbacks and hardtops, the windows are identical to the original Ford assemblies, right down to the Mustang lettering on the glass.

Replacing the Mustang quarter windows in the rear is a standard R&R operation. Gaining access to the nine retaining nuts for each window is the hardest part. For a hatchback, you must take off all the plastic trim in the back, on the inside. Typically, you will encounter tiny Phillips head screws, and you will require the proper socket in order to unbolt the front seat belt mechanism on both sides of the vehicle.

Quarter windows, i.e. the windows found just forward of the rear window of the car, present an obstacle for the Ford Mustang enthusiast. Starting in '87, Ford went with a new one-piece vulcanized rubber quarter window. If you need to replace your Ford Mustang windows, specifically the quarter windows for mustangs year 87-93, you can get a pair for $599.99 which are easy to install. The Mustang quarter windows are made by an original parts manufacturer, and are an excellent and affordable option to "patch-and-paint" kits. These measures simply do not work long term.