Is anybody aware of how to disable the occasional but regular sweep of the rear wiper when driving forwards with the wipers on. It was raining heavily today but whilst on the motorway there was little water going in the rear screen. However, about once a minute the rear wiper would sweep regardless and sounded rather dry at times so I'd like to be able to disable this.   I've checked the wipers menu in the vehicle section of the infortainment, and this provides me the option to disable