Will leaving the rear window open during rain affect the car?
4 Answers
Leaving the window open allows rainwater to enter and wet the interior seats, but it has minimal impact on the car. Types of car windows: Car windows are typically divided into four types: front and rear windshields, ventilation windows, heat-insulating side windows, and sunroofs. The front and rear windows of a car usually use curved glass that provides good visibility and an aesthetic appearance, secured with rubber seals embedded in the window frame or specialized adhesives. For natural ventilation, side windows are often designed to move up and down or back and forth. Introduction to car windows: As early as 80 years ago, glass was installed on the Ford Model T, using flat glass at the front of the cabin to protect the driver from wind and rain. In the decades since, the glass industry has gradually become involved in the automotive sector, developing various types of safety glass such as laminated glass, tempered glass, and zone-tempered glass, significantly improving the performance of automotive glass.
Last time I made the same mistake—left the rear window open during heavy rain, and the car got completely soaked. The seats and floor mats were waterlogged and took forever to dry. After a week, they started molding and emitting a nasty sour smell. Cleaning it up was a headache; I spent hundreds hiring someone to dehumidify and remove the mold. I was also worried about damaging the car’s audio wiring—if it short-circuited, it’d be even worse. Now, before parking, I always press the lock button to check the windows. I also keep moisture-absorbing bags or silica gel packs in the car to prevent dampness. Rainwater contains too many impurities, and prolonged soaking can corrode metal parts, like rusting the seams under the door frames—repairs for that are insanely expensive. My advice: if this happens, immediately open the windows for ventilation or use a fan to dry it out. Don’t delay; protecting the interior can save you a lot of money.
As a driver, I have to say this is indeed a big problem. Rainwater flooding into the back seats directly soaks the fabric and plastic components. Over time, mold and unpleasant odors are inevitable, which not only affects driving mood but may also cause health issues. Electronic components like rearview mirror switches or door locks are prone to short-circuit failures, making repairs time-consuming and costly. The most critical issue is rusting metal parts, and it gets worse if the drainage holes at the bottom of the doors get clogged. I think some preventive tips include developing the habit of checking the windows before getting out of the car, and installing a simple rain sensor reminder device can also help. If discovered, deal with it immediately: use dry towels to absorb surface moisture, take it to a professional shop to use a dehumidifier for the interior, and maintain a dry environment.
Maintenance experience tells me that when the rear window is left open and rainwater pours in, the interior absorbs moisture and is highly prone to mold growth, especially the carpets and seat cushions, which become breeding grounds for bacteria. Water can also seep into the electrical system, commonly causing short circuits that damage control modules such as the window regulators, with repair costs ranging from hundreds to thousands. There is a high risk of corrosion in metal parts, necessitating regular checks of rust-proof coatings. It is recommended to remove accumulated water immediately upon discovery, avoid prolonged parking in damp conditions, and regularly clean the interior with a damp cloth for ventilation. Simple tips include repeatedly confirming the window closure status after parking.
