I noticed that both my fog lamps were very cloudy on the inside.
Here is how I fixed that :
1. remove the front wheel.
2. remove the little door in the front fender well.
3. unplug the fog lamp bulb.
4. using a T20 Torx, remove all 3 screws that mount the assembly.
5. there are 2 'bearing' points and an adjuster. By prying the bearing joints ( carefully )
and screwing the adjuster in/out, you will be able to release the bulb holder from
the light assembly and swivel the bulb mount around and out of the way.
6. using a thin piece of wood or plastic, clean the inside with a micro-fiber cloth.
7. place the rubber o-ring in the housing, and re-assemble the light socket to the housing.
8. adjust the screw ( also T20 BTW ) so the light socket is even on both sides with the housing ( pressing on the light socket helps to seat it )
9. put it all back in.
10. do the other side.