External body parts constitute the non-structural, visible components affixed to a vehicle’s chassis, providing aesthetic form and critical protection to underlying systems. These parts—including fenders, doors, hoods, and bumpers—are typically constructed from stamped steel, aluminum, or composite materials for impact resistance and weight reduction. Precise panel fit and surface finish are essential for aerodynamic performance and corrosion prevention. Many components integrate mounting provisions for lighting assemblies, trim, and sensors. Replacement necessitates adherence to factory torque specifications to maintain structural integrity and safety system functionality.