Scratches on windscreen caused by Ice scraper

LOL....Thats happens with the Auto Wipers on the DS4 if I turn over the engine while Im doing it

Quite funny really

It happened the other week with the Merc Sprinter mini bus when the screen was frozen.  Either I had left the wipers on intermittent the night before or caught them with my hand when I switched the ignition on.  Either way they tried to sweep the screen but as the drivers side was stuck to the screen it just snapped the arm clean off!  Whoops.  Apparently they are designed that way so they don't burn the motor out.  Had to swop the blades over so I could do the school run.