Where´s that quote from? Note that it does not mention TEMPORARY import. I guess that´s what you´re planning to do, right – you don´t plan to keep the vehicle in Thailand permanently, do you?
Permanent import could be harder and very expensive to do... But if you´re arriving by air to BKK Suvarnabhumi, it should be relatively straightforward to get a temporary import permit on arrival. At least that´s exactly what we got 4 yrs ago, and following this site, many others have done the same, some just lately. I was warned not to ship by sea to BKK seaport, not sure if things might have changed by now, but by sea I´d still consider Port Klang in Malaysia.
Thailand is not in the carnet system BTW, so if you have it, it is ok to have this document with you, when importing the vehicle. But to possibly avoid unnecessary problems later on, I would not have them stamp it (in that region, only see that you get it properly stamped in, and out, if you take your vehicle to Malaysia or Indonesia).
A tip: ask Tradelanes (located in Melbourne), if they would be able to arrange the shipping also from NZ. I shipped with them by sea from Australia to Europe, and they seemed to know their stuff, and price was reasonable. I actually sent the crate from Sydney, but they used their agent there, and everything including payments was handled through them, so I never had to go to Melbourne to arrange anything.
Our experiences importing to Thailand in 2008 here:
MOTO1 - Matkalla