How does water enter the car when the sunroof drain is blocked?

[LilahMarie]

When the sunroof water channel is full, water directly enters the headliner and usually seeps out from the A-pillar and C-pillar. Below is relevant information: 1. Air circulation: The car sunroof is installed on the roof, effectively facilitating air circulation inside the vehicle and increasing the intake of fresh air. Additionally, the sunroof can broaden the view and meet the needs of mobile photography and videography. Car sunroofs can be roughly categorized into: sliding-out type, built-in type, built-in flip-up type, panoramic type, and curtain type. 2. Ventilation method: The car sunroof changes the traditional ventilation mode. Wind blowing in forms an airflow that draws out the stale air inside the cabin. When the car is driving at high speed, air flows rapidly around the vehicle. When the sunroof is opened, a low-pressure area forms outside the car. Due to the difference in air pressure inside and outside the vehicle, the stale air inside the car is drawn out, achieving ventilation and keeping the cabin filled with fresh air.