QUITE A MAZE!
At the back of the car can be found a pair of radiators, using a complex network of ducts to cool down the gearbox, and probably the ERS as well.
The lower cooler (white lines and arrows) is fed with pipes that stem from the side airbox ducts and merge back as a trapezoidal section where the radiator is attached.
As for the upper radiator (see red lines and arrows), it uses cooling air from the upper part of the main airbox intake, which emerges higher up and connects to another pipe visible on the middle picture.
Finally, the lower part of the main airbox intake is a compressor feed (see blue arrows).
As one can notice, the internal ducts sport very sophisticated shapes, the result of CFD (for computational fluid dynamics) sessions that teams use in complement of their windtunnel work.
