[shane55]

The main reason for headlight washers other than actually washing them is for driving in cold conditions....mainly falling snow. Where a standard halogen unit will generate enough residual head on the face of the headlight to melt any snow off, a xenon unit runs much cooler and doesn't become as warm therefore in cases of freezing rain/snow the headlight will become obscure, reduce visibility and dazzle oncoming drivers. It is then necessary to wash the headlight with screenwash containing anti-freeze to "clear" the lens.