Fog lights on the front make your car more visible, especially the yellow lamps. They may help you to see better, but the main purpose was to be visible to oncoming cars.

A bright red rear light has a similar function of making you more visible from the rear. Only one, though, so following cars don't panic and think you're braking. The single, bright red to the rear is distinctive, isn't it?

BTW, I think US cars like the Grand Prix have bright rear fogs. When you get passed by a car with the fogs on, notice if there are brighter light(s) on the rear.

Best Regards,
Jim