Wheel arch liners, also known as inner fender liners, are protective covers installed inside a vehicle's wheel arches. Typically made from plastic, rubber, or synthetic fabric, they serve several purposes:

• Protect the wheel well from dirt, debris, water, and road salt.

• Prevent corrosion and damage to body panels and internal components like wiring and suspension.

• Reduce noise from the road and tires.

• Improve aerodynamics in some vehicle designs.

They are usually fitted between the wheel and the vehicle's bodywork and are found in both front and rear wheel wells.