If not mistaken the afterwhipe can be turned off with vcds/obdeleven, but don't quote me on that. But i think i have seen it between the codes i think.
Personally i like it as often there is still some left over water that gets whiped off with that extra whip.
Maybe you need a new set of whipers or you have something on your windshield (rainX) or something in your water?

Can't go wrong with the Bosh aero ones (or how they are called). Ideally you better replace them yearly before winter.