What To Do If Your Car Gets Water Damage: Sunroof or Windows Left Open in the Rain

It’s a scenario more common than you might think: a surprise summer rainstorm rolls through, and your sunroof or windows were left open. Whether it was during a quick run into the store or an oversight in the driveway, the result is the same — water in your car’s interior.

At Joe Davis Autosport, we’ve seen the aftermath of unexpected water intrusion, especially in European vehicles where advanced electronics and interior materials are highly sensitive to moisture. What might feel like a minor inconvenience can quickly escalate if not handled properly.

Here’s what you should do — and not do — if your vehicle gets soaked.

Why Acting Quickly Matters

Modern vehicles, especially European makes like Audi, BMW, Volvo, and Mercedes-Benz, rely heavily on integrated electronic systems. Many of these control modules are located beneath the seats or in the floor — areas that are vulnerable during interior flooding.

When water enters the cabin, it’s not just about drying the carpets. Electrical systems can short out, safety features can be disabled, and corrosion can begin within hours. Prompt action is essential to minimize damage and repair costs.

Step-by-Step Guide: What to Do After Water Gets Inside Your Vehicle

1. Begin Drying Immediately
• Use clean, absorbent towels to blot and soak up standing water, especially from seats, cup holders, and carpets.
• Use a wet/dry vacuum if available to extract water from fabric and carpeting.
• Position fans to circulate air through the interior and leave windows cracked in a secure area to aid ventilation.
2. Remove Floor Mats and Seat Covers
• Take out any mats, covers, or removable cushions and allow them to dry separately. These items can trap moisture and promote mold if left inside.
• If seat cushions are saturated, professional drying or replacement may be necessary.
3. Avoid Starting the Vehicle If Electronics Seem Affected

If the car isn’t behaving normally — for example, if warning lights are illuminated, systems are unresponsive, or the electronic parking brake won’t disengage — do not attempt to drive it. Moisture may have compromised one or more electronic components.

In some cases, vehicles will prevent driving entirely as a safety measure. While frustrating, this is intended to protect both the vehicle and the driver from further damage or unsafe conditions.

4. Contact a Professional for Inspection

Even after surface moisture is dried, underlying systems may still be at risk. At Joe Davis Autosport, we perform comprehensive inspections that include:

• Electronic system diagnostics and fault code scans
• Evaluation of affected modules, connectors, and insulation
• Verification of critical safety features such as ABS, airbags, and electronic brakes

Early assessment can prevent long-term issues such as corrosion, mold, or intermittent electrical faults.

Common Symptoms of Water-Related Electrical Damage

After initial drying, be alert for any of the following signs, which may indicate ongoing electrical problems:

• Dashboard warning lights remaining on
• Malfunctioning infotainment or climate control systems
• Windows or locks behaving erratically
• Vehicle refusing to shift out of park or disengage electronic parking brake
• Interior odors or signs of mildew

These issues are often linked to moisture damage in wiring harnesses or control modules, particularly in European vehicles where system architecture is tightly integrated.

What Not to Do

• Do not assume the vehicle is fine just because it starts. Moisture-related electrical damage can be delayed and may not show symptoms until corrosion has set in.
• Do not use excessive heat to dry the interior. Hairdryers or space heaters can warp trim, damage upholstery, and pose a fire hazard.
• Do not ignore unusual behavior. If the vehicle is acting differently in any way, have it professionally inspected.

Preventing Future Incidents

• Always double-check that sunroofs and windows are closed when parking, especially during warmer seasons when spontaneous thunderstorms are common.
• Consider weather alerts or reminder notifications if your vehicle offers them.
• If your vehicle has a history of leaks or clogged sunroof drains, it may be worth having the system inspected and cleaned as part of your routine service.

Trust the Experts in European Vehicle Care

Water intrusion isn’t just inconvenient — it can pose serious risks to your vehicle’s electronics, interior, and safety systems. If your car has been exposed to rainwater due to an open window or sunroof, don’t take chances.

At Joe Davis Autosport, we specialize in European vehicle diagnostics and repair. Our team uses manufacturer-level tools and procedures to assess and repair water-related issues thoroughly and efficiently.

Let us help you get back on the road — dry, safe, and confident.