Tjaartk,
Sorry the delay in responding back. I have been digging around trying to find a solution to your issue. From what I can tell, the PLX device should work regardless of the fact it is a JDM model. At around 2007, nearly all Asian auto manufacturers adopted the US Spec OBD II model.
From talking with PLX, there may be some JDM-only issues that may causing the complication withe the device.
Check out the following link:
PLX Devices OBD Compatibility
You Z should use the ISO 9141-2 setup. Take a look at your OBD connection under your dash and see if the correct pins have wires running into them.
Based on what PLX states, some non-US spec models will have multiple OBD protocols running at the same time. This can confuse the PLX Kiwi device and prevent it from operating properly.
Let me know what you find out!