Some 2004-2009 Prii (Generation II) are equipped with fog lights. (I believe that all of these also have HID (high intensity discharge) headlights. The one that I did notice that had fog lights and the more common and less expensive halogen headlights turned out to have a salvage title, so I assume it had headlight assemblies from a different car.)
Now, I’m not a huge fan of fog lights. I don’t quite understand what they’re for; I figure they must be kind of elitist if they are unnecessary but some people choose to have them.
But if they’re there, they may as well work. And I see sooo many Prii with cracked fog light lenses. Some are cracked so as to have a hole in the lens, and that doesn’t leave much chance for a bulb inside to survive for very long.
I have seen at least one Prius that appears to have some sort of plastic protective layer on the lens. Unfortunately, this particular car now simply has black spots in the middle of the fog light lens where the plastic has discolored.
So I’m planning on trying to design a little rock deflector/lens saver. It sounds like the perfect candidate for a 3D printing project.
Maybe Subaru has the right idea…