It is not the greatest quality on a cab, you pick up a lot of background noise if you have it higher than the lowest setting and because of where the mic goes (on the wrong side of the overhead light fitting) you need to have it higher sensitivity.
I ended up taking my mic apart and have it sticking out of the windowscreen lining straight infront of me, shields it from outside noise and its infront of my mouth
Latest firmware AA works with my Nokia N97 perfectly including phonebook
I had a CK3200 and the quality was a lot better only got the Audi Bluetooth to add the option of the Speech Dialogue System to control the satnav, radio etc etc