It allows you to switch between speeds on the wipers. With the lower end models you only get 3 speeds. really slow. fast. and faster. The delay lets you slow down or speed up each of those modes. My girfriend has a delay wiper switch and i have the p.o.s. one. I hate getting into my car when its raining because it's either too slow and too fast for the rain. Not that it matters too much when it's faster, it's just annoying not being able to control it more.
does anyone know if it matters if it's for a hatch or not. I never paid much attention to my girlfriends (sedan) if it has the movement of mine (hatch) with the rear wiper. or are they all the same?