Why do some cars only have a fog light on them. And it is a rear fog light. Many people think that this is because automakers cut corners in order to cut corners. In fact, this is in compliance with the law. Because the brake lights and fog lights on the car are red. However, the penetration of fog lights is stronger, that is, the fog lights are more dazzling, so the fog lights and the brake lights are distinguished in order not to be mistakenly identified by the car behind. Therefore only one rear fog lamp is installed. And this rear fog light is generally located on the driver's side.