There's no microphone in there if you don't have the ConnectNav+. I've fitted one for my Parrot kit in there but have yet to see if it's loud enough or picks up too much road noise, etc.
If the Parrot one is unsuitable, I'd like to get hold of the factory microphone or a small enough equivalent, and connect that to the Parrot kit using a 3.5mm jack. I'm not sure how easy that would be, but it would be worth it. My plan is to have nothing on view in the car at all, except maybe the Parrot display if I want it.