In the United States, headlight washers are not very useful, unless you live in a place where there is a lot of salt, mud, snow, or dust on the road. The high pressure headlight washer system on some Audi, BWM, and Mercedes-Benz models does not work very well. I have seen them function on many different occasions, and they are not very efficient. The ones that really work great are on Volvo and Saab, which employ a wiper and high pressure wash. As the wiper moves, cleaning fluid is sprayed onto the headlight. These actually clear dirt and grime stuck onto the headlight glass. It is also very useful in Sweden and cold climates. Just imagine your windsheild covered with bugs and dirt. Spraying water and soap onto it will do absolutely nothing, making it even worse in some cases. Using a wiper and soap water makes all the differnce, it actually cleans!