There is a crucial part named wiper blade in the safety system. You must know how it feels when you are driving in a pouring raining day, but you cannot turn the windshield wiper on and your windshield wiper cannot make the windshield clear at all, and you have to drive your car extremely slowly to avoid any accidents. Wiper blades are made of rubber. The depreciation of a wiper blade depends on where do you live and drive. Without a well-worked switch, it is still useless even you have the best windshield wiper. A simple way to see if the windshield wiper switch is ok is try to turn it on and off and see if the windshield wiper works as command. Don't wait too late to change your windshield wiper switch as long as it doesn't work. We are glad to offer you all BMW genuine OEM wiper switch with a discounted price.