The invention relates to a device for guiding air from a vehicle front surface structure including heat exchangers (12) located in front of the engine, said device including two side diffusers (16, 18), to be disposed on either side of the heat exchangers, and a top diffuser (20), to be disposed on top of the heat exchangers, to guide the air entering through air inlets from the bumpers of the vehicle to the heat exchangers, and is characterized in that the side diffusers (16, 18) and the top diffuser (20) are provided with an attaching means capable of ensuring attachment of the top diffuser only on each of the side diffusers.