How do you turn them on?

 

They come on when your headlights are on and you use the windshield washer fuild.

 

Really? lol Thanks!

 

I had the same question and had to ask too. Of course, mbz300sdl is correct. Its an option I never would have thought to put on a car. I guess heavy snow, dusty roads, or bug infested regions inspired some car designer to come up with the idea. As far as I'm concerned, if they malfunction, I'm removing them.