On the back of a car there are tail lights, turn signals, and brake lights. Cars also have back up lights that tell people when the car is in reverse.
"Back up lights" are the same as reverse lights. Lights that "turn on" when vehicle is put into reverse gear to illuminate the rear of the car so you can see when backing up.
Most likely the reverse lights were attached to the light bar.
Never known of a car to have fog lights in rear , only reverse lights
Have you checked all the lights? Reverse lights, tail lights and brake lights?
To let others know that you are breaking.
look down by the transmission under the car.