window wiper regulating
 

everytime i wash my w211 , i lift the window wipers. I noticed that they have damaged the hood, the front edge of the hood has been stratched down to the metal. I tried to unscrew some bolts, but wiper doesnt seem want to move

Before turning off the car, turn on the wipers and switch off the ignition when wipers are in vertical position resting on the windshield and remove the key. Pull the wipers away from the screen. You can then wash the car and then put them back on the screen after washing. DON'T turn the ignition on when wipers are away from screen or you'll damage paint on the hood.

Don't unscrew the wiper arm fastening nuts and force the arms to move - you will damage the splines and most likely your wipers will not work no matter how tight you make the nuts.

It is possible to lift the wipers, from the rest position, to clean the blades and area without damaging the hood.

In the grand scheme of things, it was not the best design MB Engineers ever came up with. ;-).