Bit early I'd say, mats haven't even been ordered or paid for yet. They are still in the land of the rising sun as far as I'm aware.
IMMACUL8 lives in West Oz and he asked me to check on postage etc and the response I got was:
Hi Mate we can arrange freight to Perth no problems, we don't actually use Auspost much because of their silly size limits - we have a range of courier companies that we use and we'll certainly be able to find the most appropriate way to pack it and send it to make sure it arrives safely, at the cheapest possible price Not sure how they will be delivered to us from Nissan, experience says it'll probably be in a box that's twice as big as necessary though! Cheers, Aaron IMPORT MONSTER
They deal all over the country so I think they will have it covered.
I'd wait, I'll definitely let you all know when the supplier has them in Australia and ready for us.