Fascias need to fit precisely for safety systems to work properly. Materials and construction are critical to ensure they fit accurately and do not warp or bind with steel body panels, causing them to rust or delaminate.

Critical for safety, performance and passenger comfort, windshields provide nearly one-third of roof strength. Passenger airbags rely on them for proper deployment. Drivers and collision avoidance cameras also need to see accurately through glass for optimum safety and drivability.

Today’s sheet metal parts, such as hoods and quarter panels, are often integral to chassis structure and safety designs. Performance issues such as lack of corrosion resistance, poor fit and appearance consume extra labor hours and add to callbacks from customer complaints.

Inferior headlamp assemblies may have improper alignment, defective seals or may be prematurely yellow, which can diminish light output and hamper driver safety.

Along with convenience features like heaters, retractors and remote adjustment, proprietary crash avoidance and lane departure systems are now built into many side mirrors, making them increasingly difficult to reproduce in the aftermarket.