1 - About Extra fan: +1 with Yorgos. early vehicles were fitted 'upon request' (sul richiesta) with an additional fan for rear window, before resistors were inserted in the glass.
2 - About the foot vents, they are fed directly from the windshield grill. Some metal ducts in the fender, welded along the 'A' pillar drive directly FRESH air to the feet. So don't expect this to prevent from the cold bite in winter !!
In fact it was designed to trap efficiently moisture in the sill area to improve efficiency of rust in this area (if needed ??)
No need to say they stay closed most of the time. Hopefully there's a sealing element that prevent the duct from leaking inside the cabin
Anyway, owner's manual states clearly how air is managed in a Giulia. Anyway and watever you do, you'll freeze in winter and overheat in summer...
regards
sebastien