Quarter panels refer to the side panels on a vehicle, specifically referring to the areas located between the front and rear doors. These panels are an essential part of the car's structure and provide support for the body while also adding design elements that distinguish one make or model from another. Quarter panels can be made out of various materials such as metal, fiberglass, or plastic depending on the vehicle manufacturer’s specifications. They play a crucial role in protecting passengers from impact during accidents and are designed to absorb energy upon collision.