I wouldn't use it with the windows down if I were you. I use mine (windows up) with my Blackberry all the time, and it sounds great at my end. It's not the greatest quality for whoever I'm talking to though. It's fine, but not great. The microphone is ontop of the stereo, just in front of the display. IMO it would make more sense to put it on or near the steering wheel, but what do I know.