I have a nuvi 1300 (US), and have used the logo.bin in this thread to enable the JCV, LA which is great, however it would be nice to have Routes. I haven't tried to cross flash international firmwares like JPN 1360. In this thread:
[Only registered and activated users can see links. ]

the guy seems to have successfully flashed his 1300 with CHN 1495 prior to firmware 5.70 (but was using boot.bin from his 1300 - although the latest firmware 5.70 seemed to have caused some problems). Anyone have any comments? I was under the assumption that you shouldn't cross flash a firmware not "meant" for your series, like you shouldn't put the 1450 firmware on the 1300 (even if you mod the boot.bin) but it was OK to use the international firmware for your model if you keep the boot.bin the same