Actually, the Parrot comes with a cheap condenser mic that is faked out to be unidirectional with the plastic shrouding around it. True directional mic's cost a whole lot more and typically have some form of dsp power involved.
If you would like to increase the sensitivity of the mic in the oem position, you might want to try removing the mic from the plastic (as parrot ships it) and sitting it behind a thin piece of foam.
That said, I haven't done this. My new position for my mic is top-left of my rear view mirror.