There's an equally simple system I've seen on a cataway drawing of a Fulvia HF. A strip of plastic or material comes up over the top of the door and hangs down the door panel. The strip and panel are fitted with press studs. If you pull on the strip the window raises and vice versa. Once in the postion you want you attach the press stud to the neares one on the door panel. Very simple, especially as my passenger window mechanism seems to have seized up.