A method for operating a vehicle system is provided. At least one damping element is provided between the pump unit and a portion of the housing to decouple the noise of the pump unit. Methods for producing a maize plant that comprises crossing hybrid maize variety 37Y12 with another maize plant. The replaceable filter leafs include a filter envelope consisting of a filter panel, a nozzle member on the filter panel and defining a passageway adjacent an opening in the filter envelope for conducting fluids therethrough.