Not compatible with BOSE system or Navigation system.
Not all Mazda 6 supports external CDC connection, internal modification might be needed; Mazda 6, produced from Nov. 2003 to Sep. 2005, needs to solder a jumper or a 0-ohm chip register on location L716 in its head unit
RX-8 radio firmware version must be v9.55 or later, v10.1 and v9.81 not supported. (Note to check the radio firmware is available).