Race cars have more flexibility as to the placement of engine accoutrements. A typical air intake setup uses smallish NACA ducts in each rear quarter window (plexi) which lead directly into an airbox/air filter in the engine compartment or a remote air filter box in the rear seat area, then to the engine intake.
In my limited testing with my Fluke meter and thermocouple, the air temperature inside my filter housing is about the same as ambient temperatures .... at speed.
Arrow points to thermocouple wire:
When the car is idling, the engine compartment temperature rises due to reduced air flow into the engine compartment.
Sherwood