Hopefully you have only lubrication problem.My '99 C230 started to do the same thing a couple days ago.The wiper stopped in the middle yesterday night 70 km before my destination.I took it apart today.The plastik gear in the wiper motor is gone.The local dealer gave me a price $500 Can.I have only 68000km! Mercedes doesn't even want to talk about goodwill warranty.Can you guys help me,where can I find this part cheaper,in Canada.?!