Is it serious if the rear window is left open during rain?

[McJack]

The consequences of leaving the rear window open during rain can be quite severe, with the most immediate issue being water ingress into the car. Below is some relevant information about car windows: Types: Car windows are generally categorized into four types: front and rear windshields, ventilation windows, heat-insulating side windows, and sunroofs. The front and rear windows of a car typically use curved glass that enhances visibility and aesthetics, secured to the window frame with rubber seals or specialized adhesives. To facilitate natural ventilation, side windows are usually designed to move up and down or forward and backward. Window materials: As early as 80 years ago, glass was already being installed on Ford's Model T, where flat glass was used at the front of the cabin to protect the driver from wind and rain. In the decades that followed, the glass industry gradually became involved in the automotive sector, developing various types of safety glass—laminated glass, tempered glass, and zone-tempered glass—significantly improving the performance of automotive glass.

[ArcherLee]

Last time after camping, I forgot to close the rear window and encountered heavy rain, which turned the entire trunk mat into a pond. Rainwater flowed along the C-pillar into the trunk wiring harness connectors, causing the car computer to constantly report errors later. Even worse, water seeped into the rear seat foam, and after disassembling and drying it for three days, the smell still hadn't completely dissipated. Everyone, don't underestimate this gap—during a heavy rain, it can let in half a bottle of water in just one minute, especially in cars with sunroofs, where water can also flow back into the rear window along the roof drainage channels. Now I've developed the habit of feeling the window gap with my hand before locking the car.

[OwenMarie]

Last time when I was taking my kid to the extracurricular class, we suddenly encountered a heavy rain. I didn't notice that the rear window was left slightly open. When I picked up my child, I found the entire back seat soaked, and water had even seeped into the cushion layer of the child safety seat. The most troublesome part was the skyrocketing humidity inside the car—the next day, the windows fogged up with visibility less than five meters. I strongly recommend using a vacuum cleaner to remove the standing water immediately and then turning the heater to maximum for at least two hours to dry it out. Otherwise, mold can start growing within just three days. Also, remember to check if there's any water accumulated in the seat belt buckles, as rust on the metal components can hinder emergency release.

[McValentina]

Leaving the rear window open during heavy rain is really troublesome. The water accumulation in my station wagon's trunk caused the soundproofing cotton to completely soak and swell. When I took it apart to dry, I discovered the spare tire well had turned into a small fish pond. The most damaging electrical issue was the corrosion of the rear window heating wire connectors, which later increased resistance and blew the fuse three times. Now I've learned emergency measures: immediately disconnect the battery's negative terminal, and use a dry towel to block the drainage holes to prevent water from seeping into the front seats. Afterwards, you must remove the door panels to inspect the window regulator tracks, as rusty rails will accelerate motor wear.

[JeffreyRose]

Last time during the heavy rain, the rear window wasn't closed tightly, and water ended up flowing along the inner steel plate of the door into the control module beneath the floor mat. During the repair, the mechanic mentioned that fixing this computer board, which controls the windows and door locks, would cost over two thousand. What's even more hidden is the soundproofing cotton under the carpet—it absorbed water and didn't dry out completely even after two months, leaving a sour smell in the car during summer drives. It's recommended to remove the seats and lift the carpet to check for rust at the welding joints of the car frame immediately after rain. Instead of using dehumidifier boxes, placing two bags of cat litter on the back seat works wonders for absorbing moisture—it's highly effective and much cheaper.

[VonRebecca]

My neighbor forgot to close the rear window of their SUV during a thunderstorm, and initially, only the surface of the seats got a bit damp. A week later, the power window started making squeaking noises, and upon disassembly, it was found that the window rails had rusted shut. Worse still, water had seeped into the B-pillar, causing the side airbag curtain sensor to malfunction and triggering several warning lights. The repairs cost over three thousand yuan: the headliner had to be removed to check if the sunroof drain tubes were clogged, and the moldy headliner foam had to be replaced. During the rainy season, remember to use a waterproof car cover when parking. As a temporary solution, you can use plastic wrap to seal the window gaps from the outside, and tape along three sides of the window frame for a secure hold.