I installed the blueooth kit for sale for 02 and beyond E46s this past weekend in my 03 M3 convertible. It worked just fine, despite everyone I spoke to at BMW NA and my local dealer assuring me that it would not work. (Note: be advised you will need to find a tech at your local dealer to reprogram the computer to turn on the bluetooth option, so keep good relations with them).

Recommend you order the parts from Chris at Circle BMW (circlebmw.com). I also recommend you install the kit yourself if your dealer won't do it (they will not install the kit in a convertible).

There are lots of factory instruction manuals at http://members.roadfly.org/bmw_e46_m3/index.html and the way to do a convertible (they are a bit different) is well documented at http://golilm.com/DIY/Bluetooth/BluetoothCab/bluetoothcab.htm

Good luck. It works great and is well worth the money!

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Link: Photos of Bluetooth e46 M3 Convertible Install (http://golilm.com/DIY/Bluetooth/BluetoothCab/bluetoothcab.htm)