The Bose audio system – which is fabulous – also includes Bluetooth telephone compatibility which dispenses with a car kit. It allows you to pair a number of phones with the car as well.
Sadly, it appears that one manufacturer’s implementation of Bluetooth differs from another and I have had some ‘issues’ getting one of my phones to work properly. I presently have a Nokia N97 for general use, a BlackBerry Curve 8900 for work and a Sony Ericsson W595 as a spare (those hyperlinks take you to the results of Mazda’s tests on the handsets).
Whilst all three phones successfully paired with the R3, the Nokia will only receive calls through the audio system and make calls only if dialled from the handset. Both the other phones make and receive calls by voice alone, which is effectively another nail in the coffin for the Nokia.