I'm using the Visteon Hands Free Kit, The Visteon URL is:
http://www.evisteon.com/prod_serv/mo...pk/index.shtml
It feeds the NAV system a mute/phone enable (+5v enable phone / 0v normal operation) and the audio signal from the phone. When you get or place a call the system mutes your current audio program and routes the phone audio to the front speakers. The NAV system display changes to "Phone" while the phone is in use. It can pair with any Bluetooth phone that supports Handsfree or Headset profile. I'm have a Motorola V551 phone and the system works excellent with it. The Visteon system supports voice dialing using your phones stored voice commands OR you can record voice commands directly to the Visteon system itself. It is very easy to use and does a good job with the voice recognition.
Michigan does not yet have a law for cell phone use, however I am a person who always uses a handsfree kit in the car ( don't want myself or others to end up as raod pizza ). I have used many different brands and types of handsfree kits from wired to bluetooth ear buds. I would have to say that this is the best handsfree kit I have used to date. The audio quality is excellent and the microphone picks up just normal voices and has good regection of background noise. People tell me that they don't even know that I'm in my car while I'm using it. That said, I have not used it with the windows down, I'm sure that would be very noticable.
The only thing I could wish for is the ability to dial by voice numbers and not just with recorded names. i.e. be able to say "Dial" "five" "five" "five" "one" "two" "one" "two" to call 555-1212. As it stands you have to have the number in your phone book and have recorded a name for that number, then you can dial just by saying the recorded name.
The unit cost me $256 + $100 (installation).