The SAAB 9-5 has rear fog lights on the back of the truck lid. They are about as bright as the brake lights. My 2000 9-5 originally came with one rear fog light (driver's side). This is, I read, to prevent people from mistaking the fog light for brake lights.
Personally I think it looks like I have a tail light out. I want symmetry. There was a simple answer and it is about a five minute job.
The wiring and bulb socket were already in place behind the passenger side lens. All it took was a screwdriver and a small set of pliers. Open the trunk and remove the plastic fasteners and handle holding the right side of the carpet lining in place.
You don't have to remove all of the lining, just enough to expose the back of the lens. The back of the fog light lens will then be exposed.
Detach the light sockets. Use the pliers and screwdriver to remove a plastic plug in the back of the lens setting in the trunk lid.
It is designed to keep you from easily putting a bulb in there (it came out in chunks for me). Then install a bulb and you now have two rear fog lights. The bulb is a 7506LL
I guess they could be mistaken for brake lights, but it would become obvious as soon as the rear brakes are pressed. Plus wouldn't mistaking the fog lights for brake lights get the other driver's attention. That is the goal of rear fog lights.
I use my rear fog lights in, well, fog obviously... and snow and very heavy rain. I run them any time the conditions could help an inattentive driver mistake my rear end for the wide open road.
Photo of the rear fog lights off
Photo of the rear fog lights on
Check local laws before driving with rear fog lights and such. In some places people will expect the single rear fog light. And all other disclaimers, past, present and yet to be realized. Searching the tubes it seems that rear fog light opinions are up there with religion and politics. I have seen civil message boards break down to anarchy when the "one v. two rear fog lights" debate comes up.
To clarify some frequent questions about rear fog lights that seem to come up again and again about when and where rear fog lights can be used in the United States-
From the State of California:
"A vehicle may be equipped with not more than two red tail lamps mounted on the rear which may be lighted, in addition to the required tail lamps, only when atmospheric conditions, such as fog, rain, snow, smoke, or dust, reduce the daytime or nighttime visibility of other vehicles to less than 500 feet."
Scroll down to section 24602 on this page to see my source:
You still want to check your local laws about rear fog lights, but this gives a good general guideline for rear fog light use in this country.