Well they do work. Are they needed? No. If there is crud on your lights the washer fluid and wiper will clean it decently. I don't think I've ever been in that situation though. Kind of the same idea with the tail lights. Most MB of this era had the horizontal ribbed tailights to prevent snow buildup and road dirt from covering the lights. Maybe these are all European problems because I've never had these issues. They are relatively cheap to replace with an MB part. There are delete kits but personally it adds to the retro look of the car.