Flap of a motor vehicle ventilation system

A motor vehicle ventilation system, comprising at least an intake housing, a plenum chamber, one or more flow conduits and one or more control flaps for distributing the air to the flow conduits, and a flap (2) arranged to control the air supply to the interior of the vehicle together with a second flap (4), said flap (2) comprising a shaft (2″), on which said entire flap (2) is pivotable, a flap surface (2′) and a sealing portion (13), characterized in that at least a first portion of the flap surface (2′) is pivotable relative to the shaft (2″) and/or another portion of the flap surface on the opposite side of the shaft (2″), in that said sealing portion (13) surrounds at least a portion of the peripheral edge of said pivotable first portion of said flap surface (2′), and in that pivoting at least the first portion of the flap surface (2′) relative to the shaft (2″) and/or the other portion of the flap surface on the opposite side of the shaft (2″) generates a return spring force, causing the flap to regain its original shape on load relief and further characterized in that pivoting occurs in a portion of the flap that is relatively proximal to the shaft (2″) and/or the other portion of the flap surface on the opposite side of the shaft (2″), which is configured more flexible than the remaining portion of the flap that is relatively distal from the shaft (2″) and/or the other portion of the flap surface on the opposite side of the shaft (2″), and wherein the return spring force is formed in the portion of the flap (2) that is configured more flexible than the remaining portion of the flap (2).