I understand that the lower grille is usually used to increase aerodynamics, but, on a car that has a hydrogen fuel cell, would an upper grille (like the main grille) be necessary like it is on petrol-powered vehicles?
Petrol engines get very hot. They are air cooled through a heat exchanger that we commonly call a radiator. A hydrogen fuel cell car is essentially an electric car that gets its electricity through a hydrogen fuel cell. Fuel cells can run warm and could use some climate control. They typically also use some oxygen from the air but both of these situations could be handled in a number of alternative ways. So not necessarily.
