Quarter Panel
Part : QTR
On an automobile, a quarter panel (or rear wing) is a body panel that covers the section between the door and the trunk. They are typically made of sheet metal, but are sometimes made of fiberglass and fibre-reinforced plastic. They are the parts of the exterior of the car that is left once the hood, trunk, roof, doors, bumpers, fenders, lights, and plastic trim are taken away. They typically wrap around the wheel wells. Damage to these panels does not affect the frame so these panels can be replaced with little effect on vehicles safety and crash worthiness.
This Panel is architectured differently for various types of vehicles. hence for every Car the panel has different sizes and lengths to where it may extend. As shown in the pic it is not formaing a part of the upper body. This type if design is very simple to replace in case of damage. The others extend themselves close to the front door from top and bottom. There is a cut generally visible if you follow the part line till the front door to reveal a 'C' shape. These 'C' shaped parts are hard to replace as this involves removing the Windscreen as well among other tasks.