A motor vehicle is equipped with an outside air introduction assembly 104 functioning to introduce the outside air into a radiator 92 in an engine cooling system during driving, as well as with an outside air introduction assembly 114 functioning to introduce the outside air into an engine 22 during driving. The motor vehicle is also equipped with shutter plates 106 capable of regulating the amount of the outside air to be introduced by the outside air introduction assembly 104, as well as with shutter plates 116 capable of regulating the amount of the outside air to be introduced by the outside air introduction assembly 114. The shutter plates 106 and the shutter plates 116 are individually actuated and controlled to increase the amount of the outside air to be introduced by the outside air introduction assembly 104 and the amount of the outside air to be introduced by the outside air introduction assembly 114 with an increase of temperature of cooling water detected as a cooling water temperature Twe in the engine cooling system. Such actuation and control assures the adequate cooling performances to cool down the cooling water by the radiator 92 and to cool down the engine 22.