Rigid exterior plastic components (such as side moldings, mirror covers, wiper cowls, and rear diffusers) are injection-molded from raw, unpainted polymers—primarily Polypropylene (PP) or Acrylonitrile Butadiene Styrene (ABS). These materials feature a molded-in micro-texture that scatters light to create a matte look. Because they have no protective clear coat shell, they are directly exposed to photo-degradation. Solar UV rays split the delicate polymer bonds, causing the plastic to leach its internal stabilizing oils. This structural breakdown leaves behind a dry, faded, oxidized white chalky crust that destroys the vehicle's contrast.