For rallying like cid498 said.
Roof scoops purpose.
The high operating temperatures in the engine compartment result in intake air that is 28 c 82 f or warmer than the ambient temperature and consequently less dense.
Anyone has idea.
In most modern vehicles internal combustion engines breathe under hood air or air ducted from under the front bumper through plastic and rubber tubing.
Roof scoops for some rear or mid engine cars are used for the same reasons a hood scoop to flow air to the intake for the motor or an inner cooler.
I might be wrong then but another thing is it creates downforce.
The tailored ventilation system purpose built for the harsh australian climate.
Yes the roof scoop will give some air flow in the cabin however there are far more efficient and aerodynamic ways of doing so.
I have read the answers below and they only tell half the story.
Hood scoop functions cool air.
For rally cars a hood scoop is used to create high air pressure in the cab of the vehicle to help reduce dust from entering and improve visibility.
All they are is a fresh air inlet for the cabin if you ve ever watched any.
Hood scoops are for cooling the engine or engine components.
However in an effort to shave every spare pound off my 93 hardtop i have decided to remove the whole ac system.
The proven effectiveness of cross ventilation has been well documented but often neglected.
I do like the draining mechanism though.
Ok its for looks and for some of the cars its got their functions midengine uses it for air intake since their engine does not get enough air from the back not like front engines do they put theirs on the roof or sometimes you see them on the sides nsx and mr2 got them customized.
Roof scoops on street cars are lame.
Just a quick video on how i installed my roof scoop and vent on my 2004 subaru sti thanks for watching.
Like a spoiler creates downforce based on airpressure differentials a scoop if some do as i said at first and move air into the passenger area then some that dont are merely for downforce will force air into its air box and creature a pressure difference that also creates downforce the same as wings and spoilers.
The roof scoop is unlike any other roofing ventilation.
It is a complete system which creates cross ventilation within the roof space.
If this was the real reason then every track race car.
The large roof scoops used on world rally cars and race cars are usually there to provide fresh air for the driver.
Deep 6 rally team merch and also random car sticker.