When another vehicle is spewing exhaust fumes in the vicinity, the air filtering system does not seem to filter-out the noxious fumes. Attempted resolving problem by enabling Recirculate Cabin Air feature; however, the Recirculation feature will shut-off unexpectedly without any noticeable pattern. Regardless of setting, outside air entering the cabin via air vents should thoroughly filter outside air where noxious exhaust fumes, etc., do not fill the vehicle's cabin. This has been a perpetual issue. When taking it to a Dealer for inspection, they merely say that the system appears to work as designed by not yielding any error codes (?)!