Also, in addition to what Mr. Hayes mentioned, fog lights are for
illuminating the sides of the road in foggy conditions so you can see the
limits of where you can steer the vehicle. Having lived on a gravel road
for fifteen years, on a mountain that fogs up every winter, I've seen enough
folks with misconceptions of what fog lights are and do. They are less
necessary on roads where the white outer line (the fog line) is visible, but
when you are on gravel and can't tell where the sides of the road are, the
wide angle illumination from the fogs really helps a lot.
On another note, it is actually illegal in Oregon to drive with aftermarket
fog lights on while there is oncoming traffic. There may be a reasonable
limit to what your dealer can do, to remain within the law where you are
located.
~Brian