Vehicle cabin ventilation

A vehicle has a passenger cabin and a ventilation system (10, figure 1A) including a vent 40 to discharge air into the cabin. The air may be heated or cooled. The vent comprises a housing 43,55 defining a vent inlet 51, vent outlet 42 and a chamber therebetween. A flow divider 60 splits the chamber into first and second passages 46,47 and includes a trailing edge, which may take the form of a bulbous member 62 or a converging end (62', figure 6). The first and second passages meet at the trailing edge such that respective ventilating air flows 'A1','A2' flowing along the passages converge and combine to provide an outward flow 'A' from the vent outlet. A valve element 52 may be rotated to control the relative proportion of the air flows and so determine the direction of the outward flow. The vent outlet is a curved, elongate slot that ideally follows the curvature of a dashboard it is in to extend across a width of the cabin. The trailing edge of the flow divider is correspondingly curved. A gap 'G' between the valve element and flow divider may prevent whistling noises.