[Kiwirover]

I can confirm that JDC. The Jap Nav units will only work in Japan. (I have recently upgraded my Jap highline to a Mk4 BMW unit for this reason).

The Jap FM radio module will work in NZ and Aust (and I presume the UK) but only when used with a band expander.
The audio quality and success of this depends to a good degree upon the quality of the band expander. Additionally the frequency displayed on the highline screen will be not be correct (10, 12 or 14 MHz below the correct frequency depending upon the frequency of the band expander used).

I use a 14 MHz band expander on mine and have to admit that the Jap module with one fitted is surprisingly good. I guess that this is helped by being a reasonably good receiver to begin with.

When selecting a band expander go for the best you can afford. The higher frequency units have less “blank” spots and are therefore less prone to co-channel mixing. However this does depend to a large degree on your local FM transmitter frequency spacing and environment. A knowledgeable local dealer/technician should be able to assist further.