Had the same thought last night and it turns out quite expensive
Called up Seaway/Kiwi, they said they want $2k just to ship it from Auckland to Brisbane (then road transport down to Sydney), add AQIS charges and cleaning, add customs and engineering to get it on the road - adds up to almost $4k to bring it over then add rego and the cost of the Mini itself. Fark, for that money I might as well buy one locally and stop being hated by the Mini owners in Unzed for stealing their Minis out of their country
Oh yeah forgot the import approval 50 big ones too..