Hi,

It sounds like you have the Japanese Z4 with the Japanese system.
I have converted some of these from Japanese to Euro system.

Note you must use Mk4, the Mk3 cannot work in a Z4.

The 18p connectors are available from BMW - refer to the www.realoem.com website, see this page here:
http://www.realoem.com/bmw/showparts...80&hg=61&fg=15
You need item #9 (18-pin connector), x 2 connectors
2 x pieces Part 61131383852
Plus you need some pins, about 4 will do, because most wires can be removed from the Jap plug and inserted in the Euro plug:
4 x 61130005197
You will see some wires (power, ground) have to have new pins fitted.

Remember: you also need to join the FM antenna (it loops through the Jap nav, it is used for VICS reception in Japan) once you disconnect the Japanese nav, otherwise you have no more radio reception, (or reduced radio reception). I used a custom-made SMB-SMB coax cable, 100mm long

Also, the Jap GPS antenna connector (type: Fakra) will not fit the Mk4 because it does not have the right locking mechanism. I used another SMB-SMB extension lead, also 100mm long, and used tape on the Fakra-to-SMB connection to secure against vibration.

Do you know how to change the radio from Japan mode to Oceania or European mode to work in Singapore?

If you also have telephone, the phone can be changed as well, if you want.