Got in my car this morning and windscreen was covered in ice. I got my de-icer out and melted all the ice off. However when I went to switch the windscreen wipers on the one on the passenger side wasn't doing anything and appears to be broken. It looks like the mechanism underneath has broken off the passenger side. Seat say the part will cost £40 but, its so tight to get anything in there to fix it with. Am I better off doing it before MOT or waiting to see if they will fix it at the garage when doing my MOT ?