The car was familiar with very much to everybody nowadays now, many friends had had his love car, but small to the use of the car doohickey, probably everybody still is not very clear. Weather also is to become cold gradually now, numerous car advocate also know, after opening the central heating inside the car because differ with the temperature outside the car inside the car, because windshield cannot warm up very quickly, so the vapor in air arrives with respect to meeting adsorption above car window, to the car advocate the line of sight causes very big worry. Above all what is the reason that we are about to understand car window has fog after all, because temperature of car window inside and outside is different,the principle that fog has inside the car actually is, the air inside the car that cause condenses into small drip, much later formed this kind of result. Want to solve this kind of problem with respect to this from this principle so, the first method reduces the humidity inside the car namely. When car window has fog, car advocate not flurried, reduce speed first, open key-press of the dehumidify inside the car next, can reduce phenomenon of the mist since car window effectively. Of course, will warm wind blows glass also is a method, but although these two kinds of methods have fog in reductive car window, but after all oil price is so high now, opening air conditioning also is special excessive consumption of fuel and oil. Still have a method actually, a lot of old drivers are time-tested, and special economy is energy-saving.