What is the plastic frame inside the fender called?

[Katie]

Automobile fender below a piece called the bumper. Automobile fenders are made of plastic, steel, and aluminum alloy. Fenders, also known as wings, are divided into front fenders and rear fenders according to their installation positions. They are a type of cover component on motor vehicles and non-motor vehicles. Bumper composition: Plastic bumpers consist of three parts: the outer panel, buffer material, and crossbeam. The outer panel and buffer material are made of plastic, while the crossbeam is formed by stamping 1.5mm thick cold-rolled sheet metal into a U-shaped channel. The outer panel and buffer material are attached to the crossbeam, which is then bolted to the vehicle frame longitudinal beams, allowing for easy removal. The plastic used in these bumpers is primarily polyester-based or polypropylene-based, manufactured through injection molding. Bumper function: Automobile bumpers (impact beams), located in the front and rear areas of the vehicle, are designed to prevent external damage from affecting the vehicle's safety systems. They have the capability to reduce injuries to occupants during high-speed collisions and are increasingly being designed for pedestrian protection.

[DeKhloe]

From my experience as a seasoned driver, the plastic frame inside the fender is commonly called the wheel arch liner or fender liner. It sits between the tire and the car body, mainly to prevent road stones, mud, and rainwater from splashing into the engine compartment or chassis, avoiding rust and damage. I’ve encountered several instances of strange noises in my car, and upon inspection, it turned out to be this part being loose or cracked. Since it’s made of lightweight plastic, it’s cheap but prone to wear and tear on bumpy roads or in cold winter temperatures. Whenever I wash my car, I always take a quick look at it. If I spot any cracks or dislodgment, I replace it immediately—it only costs a few dozen bucks. This prevents mud and water from seeping in and damaging other electrical components. Regularly checking this small part can save you a lot of money. I recommend car owners lift the fender and inspect it every six months or so, especially those who frequently drive in harsh road conditions.

[JasperFitz]

A few days ago, I went on a road trip and suddenly heard a squeaking sound. Upon inspection, I found cracks in the plastic frame inside the fender. This part is called the fender liner in repair shops—essentially a protective cover that blocks the wheel arch gap to prevent debris from flying in. I’ve replaced it once before, and the whole process was quite simple, requiring only the removal of a few screws or clips. A new part costs less than a hundred yuan. Though it may seem insignificant, it’s highly effective at blocking water during rain or high-speed driving. Protecting this area can extend the lifespan of suspension and brake components, preventing rust-related safety hazards. Now, during every maintenance check, I ask the mechanic to inspect it to ensure the plastic hasn’t aged or deformed. After all, paying attention to small maintenance details can enhance the overall driving experience.

[GabrielFitz]

The plastic part inside the fender is commonly referred to as the wheel arch mudguard. Its basic structure consists of a curved plastic panel fixed above the tire to block debris, dust, and water from entering the undercarriage. Based on my automotive design research, plastic is used for its lightweight properties, corrosion resistance, and impact absorption capability. If damaged and not repaired promptly, mud and water can corrode the chassis or engine components, potentially leading to malfunctions and compromising driving safety. Issues can be easily identified through visual inspection, and regular cleaning of the inner wheel arch is recommended.

[OEdward]

As an enthusiast who frequently tinkers with cars, I've learned that the plastic frame on the inner side of the fender is called the fender liner. It not only prevents mud and water splashes but also reduces noise. Many modification enthusiasts upgrade to more durable materials or components with ventilation designs to enhance protective performance. I've replaced a set myself—after selecting the right size, DIY installation only requires basic tools. The key is to ensure the clips are properly aligned and sealed to avoid gaps that could let in wind or water. During routine checks, pay attention to any signs of scratches or looseness. This small modification can significantly improve driving comfort.