Driving With a Broken or Missing Rear Window

The biggest risk with a missing back window is not rain. It is exhaust. When a car moves, air flows over the roof and leaves a low-pressure area right behind the vehicle. On an SUV, wagon or hatchback, that wake can pull air back toward the rear opening, and the air it pulls in can include your own tailpipe exhaust. The CDC has described this effect for station wagons: opening the rear window can let high concentrations of exhaust fumes into the vehicle. Vehicle makers print the warning in owner manuals. They tell drivers to keep rear windows, liftgates and trunk lids closed while driving.

Exhaust contains carbon monoxide, which you cannot see or smell. Headaches, dizziness or feeling drowsy while driving with the back open are warning signs. If you feel any of that, stop, get out and get fresh air. As a rule for a missing back window, open the front windows a little so air passes through the cabin and out, instead of settling. Do not idle with the rear open, and never sit in a parked car with the engine on and the back exposed, especially in a garage.

Visibility is the second problem. If the glass is broken but still in the frame, shattered tempered glass turns frosty and white and you lose the view out the back. If the glass is gone, your view is better, but now there is a cover or the plastic sheet over the opening, and that is often cloudy. In either case, rely on your side mirrors, move your head more often and give yourself extra room to back up. The inside rearview mirror becomes a poor tool, and backing out of a driveway on a busy Forsyth County road is where it matters most.

Weather and dirt matter more than you expect. A back window opening lets rain in over the cargo area, the seats and the electronics, and the road dust that blows in covers everything. Spray from a wet road comes up and in. A heavy plastic cover, taped from outside along the frame, helps keep that out, but the tape and film can flap or peel at highway speed, so cover tightly, and expect it to be temporary. Remove valuables from the cargo area too, because an uncovered cargo space is easy to see into.

We replace back glass, and we come to you. We need the VIN, since one vehicle can use more than one back glass depending on the defroster grid, antenna lines and any factory shading. We install OEM, OEE and aftermarket glass, and a customer review confirms we reconnect rear defroster connections on back glass jobs. The workmanship is warranted for the life of the vehicle. Until then, keep trips short and keep the air moving.