The fender under the car door is called a apron. Automobile skirt introduction: refers to the skirt installed on both sides of the car body. When the car runs at high speed, it can reduce the air resistance, which has the same effect as the air dam. It is used to reduce the airflow on both sides of the car body to enter the bottom of the car body, which has a certain turbulence effect and can obviously reduce the air resistance under certain conditions. Automobile skirt material: generally divided into three materials: integrated stamping of steel plate, integrated stamping of engineering plastics and integrated stamping of aluminum alloy. Among them, the integral stamping of steel plate and the integral stamping of aluminum alloy cannot be disassembled separately, and sheet metal cutting is needed, because it is connected with the car body and the shell, while the engineering plastic material can appear separately, mainly connected with the car body through threads and buckles, and the specific material belongs to detachable connection, which varies according to different models.