The tail lights are external lights that fix to the outside of the car at the rear on both corners and are contained in either a metal or plastic housing. Part of the car's lighting setup, the tail lights are an important safety feature of the car enabling other road users to clearly see what the driver of the car is intending to do next on the road.

The tail light cover is the protective plastic casing, usually attached with screws, which fits over the face of the tail light assembly providing protection to the tail light bulbs. The tail light cover also functions to enable other drivers to clearly see the signals given by the tail light. A damaged tail light cover can distort the signals given by the tail light, making it hard for driver's to interpret what the car intends to do, which is a dangerous situation on the road. A damaged tail light cover can also stop the tail lights from working properly. It's important, therefore, to get a damaged tail light cover replaced as soon as possible to ensure your car is safe on the road.

Because of their positioning on the vehicle and fragile bulbs, the tail lights are vulnerable to being smashed and cracked, particularly in a crash but also as a result of stones and debris flying up from the road or badly maneuvered reversing. The tail light cover helps to prevent this from happening. As a result, the tail light cover instead tends to take the brunt of any damage and a common reason for replacing this part is because it's been cracked or smashed. Another typical reason for replacing the tail light cover is a damaged seal. This can allow water to leak into the tail light assembly and potentially damage the bulbs and other components.

When replacing the tail light cover it's important that you purchase one that will be compatible with your vehicle. Rear tail lights come in many different sizes, shapes and styles, as do the tail light covers, and are vehicle specific.  Purchasing a new tail light cover will ensure you get a quality part that fits the make and model of your car perfectly.