From what I learnt chatting to an engineer down at IDB in Richmond the line went like this:
4AGZE was never released in Oz, so it never passed ADR, or whatever it is, emissions requirements. So if you want to get all your froms ticked and rubber stamped you have to get an engineer to do the line "They were released in Japan and US and they have tighter emissions regs than here so it has to be ok".
And it has to run stock management.
For more info get onto Vicroads 13 11 71 (scary I know that off the top of my head) and get a list of engineers then talk to them.
If he wants pretty graphs or the like I suggest you scour the net or photoshop some up yourself.