The main reason for having a roof scoop on a rally car is to actually pressurise the interior of the car slightly.
Reasons for scoop on roof.
Due to its location the air enters clean with no dust and it contributes to keeping the temperature down as well as to keep positive pressure inside the cockpit preventing dust from entering by other car openings.
This condition can introduce carbon monoxide a colorless odorless poisonous gas in the building.
Recognized by enthusiasts as a snorkel the roof scoop offered by mso is there to intake air going over top the vehicle to cool the engine faster so if you find yourself going to the track the roof scoop is perfect for you.
Deep snow on a roof can bury a gas appliance flue causing the exhaust to enter the home.
Closed hood scoops are for the most part decorative but can offer increased aerodynamics and hence better fuel efficiency and speed at least in theory.
Excess snow on the roof can weaken and potentially collapse a structure particularly an older building with a shallow pitched roof.
Also available separately from the roof scoop is the mclaren track telemetry option ready to record your every action.
The only other reasons for a roof scoop are to cool rear mounted heat exchangers radiators or to provide intake air for a rear or mid mounted engine.
Open hood scoops are enclosed on all but three sides and raised in order to catch additional air flow particularly at higher rates of speed.
This small increase in pressure works wonders to keep out dust and sand from the rally stage.