Mazda 3 Maps Australia v16

Hello I have a Mazda 3 with Australian maps v15 and want to update these maps, but i cant read the SD card to work out how the maps are setup on the card or which directory.
Firstly is there a way to read the card as i have tried a card reader and doesnt even come up to be able to access the card.

Secondly where can i get the maps?

thanks in advance

I have one of these too..

It was 3 years out of date when the car was bought brand new...

They are a Denso propietry system and not easilly updated and for $295 they can keep it, I have used the money to purchase a chinese 7 inch unit that can do heaps more..