I was driving in the rain today and suddenly my passenger side wiper blade came loose and started rattling on the windshield as the wiper arms moved up and down. I checked it out and the problem is the metal arm no longer "clicks" into the blade socket. Is there some sort of plastic grommet or piece that goes between the metal hook on the arm and the socket of the blade? I bought a replacement blade and it doesn't click in either. Any thoughts?