Hi I have recently bought a 51 plate E46 m3. Its seems to have a retro fit NAV system already installed. its got a 16:9 monitor, with mk3 CD based system in the boot with BMW 6 DISC cd changerwhich all works. The OS version is 63 which i beleive is the lates for mk3. I have no idea about these radio modules that people talk about, so im not sure if my radio is pre 2003 or not. I would like to have a aux input that does not replace my cd changer. Is this possible??