What is the protective panel under the car door?
2 Answers
The plastic protective panel under the car door is called a side skirt. The side skirt refers to the skirt panels installed on both sides of the vehicle body, and its function is equivalent to an air dam, used to reduce the airflow entering the underside of the vehicle from both sides. It has a certain spoiler effect and can significantly reduce air resistance under certain conditions. Common door accessories include: Door glass: Provides the driver with a certain degree of side visibility, aiding in driving. Door hinges: Used to support the door, ensuring smooth opening and closing. Door handles: The interior handle is generally fixed on the door trim panel, while the exterior handle is fixed on the door outer panel, facilitating the closing and opening of the door.
I've been repairing cars for over 20 years, and that thing under the door is called a rocker panel guard – definitely not a small component. Its main function is to protect the vehicle's underbody, preventing stones, mud, and rainwater from entering the door and frame. Typically made of plastic or metal, it withstands scrapes and even helps reduce wind resistance for better stability at highway speeds. Many owners overlook it until they scrape a curb and it gets deformed. Left unrepaired, this accelerates chassis rusting, potentially costing hundreds to replace later. I recommend checking it every six months, especially in rainy areas where debris can clog drainage holes – give it extra scrubbing during car washes. I remember one case where a customer complained their door wouldn't close; turned out the deformed guard was jamming it, and everything worked fine after repair.
