The rear lights on a car are generally only turned on when the car is in use. However, there are a few different situations where the rear lights may be turned on without the car being in use.
One such situation is if the car is parked on the side of the road with the hazard lights on. This is generally done to indicate to other drivers that the car is stopped and they should use caution when approaching.
Another situation where the rear lights may be turned on is if the car is being towed. In this case, the rear lights are generally turned on along with the hazard lights to indicate that the car is not being driven under its own power.
So, in general, the symbol of a car with the rear lights on indicates that the car is either stopped or being towed.