You wont have a problem with Motorad delivering parts or being able to source them. And they are very reputable (IMHO).

All of the guys (and girls) at Motorad are pretty good but I have the most success with Dan for parts, AnneMarie is excellent for accessory stuff, and Glen is the man for bikes.
And ultimately, Carl is your final destination for getting it sorted.

Ring the main number (04 3828011) and ask to speak to Dan if you don't get your problem sorted. I'm sure he'll look after you - or at least try and sort something else out.

However, as has been pointed out, your at the mercy of the importer/distributor, and having a European bike is going to cause you frustration!
I found that out the hard way. As an example, It was going to take 3 months to get an o-ring (at a cost of $8) imported for my Husky. In the end I just took it down to a seals place and they sized it up for me at a cost of 38 cents all up

What particular part did you require? Someone may already have something for you in the country or point you somewhere.