I find the rear wash wipe screen wash works ok at low speeds and allows enough fluid onto the screen to perform a full clear but on a motorway run in damp conditions (no rain as such just road from which sticks to the back of the car) the wiper only cleans the top 3/4's as the screen wash does not get chance to roll down the screen due to the airflow and wiper kicking in which just moves the water around the top half. Looking in the rear view mirror and seeing a complete dry patch of smeared di