Why Does Water Accumulate Under the Car Mats on Rainy Days?

[Menezes]

The reasons for water accumulation under the car mats on rainy days: 1. Sunroof leakage: Most vehicles on the market are equipped with a sunroof, and there are four drainage pipes at each corner of the sunroof that channel rainwater out of the vehicle through the A-pillars and B-pillars. If these drainage pipes become clogged or otherwise obstructed, rainwater can accumulate in the sunroof and eventually flow down the headliner to the floor, causing water accumulation. 2. Air conditioning leakage: Condensation water from the air conditioning system is drained through a dedicated pipe and exits the vehicle via the chassis. If the air conditioning drain pipe becomes clogged, twisted, or detached, the condensation water may drip directly onto the vehicle floor, leading to water accumulation over time. 3. Vehicle wading: When road water levels rise above the vehicle chassis, water may enter the interior due to the vehicle not being completely sealed.