Hi Craig, I went to NZ a couple of years ago for three months. I flew into Auckland hired a car from rent-a-dent for 12 weeks which as the name suggests was a bit of a wreck but it was covered by breakdown cover and to be fair it was mechanically sound and never let me down. I bought a tent and camping eqpt very cheap and set off. I covered 11, 000 km and explored both North and South Island. As you won't have as long as that I recommend that on North Island you should visit Bay of Islands as it is the birthplace of modern NZ and very pretty, Roturua with the thermal activity and fascinating geysers and mud, Auckland itself especially the botanic gardens, museums and suburb of Devonport. Wellington is quite interesting but Hollins is right it tends always to be blowing a gale and wet and cold. I took the hirecar on the ferry to South Island which was quite expensive. South Island is fantastic, highlights are Abel Tasman National Park and the area around Nelson and Picton; the glacier country around Fox and Franz Josef; Milford Sound; while both Dunedin and the Otago peninsula and Christchurch are great. Finally I went whale watching off Kaikoura which was fantastic. I recommend the 'LonelyPlanet' guide if you haven't already got it. New Zealand is the most beautiful and friendly country on earth, the only two downsides are probably going to be the rain at this time of the year and the roads are often pretty rough and unsealed (not tarmacced) and some hire car companies tell you not to go on unsealed roads. Also local drivers are pretty uncompromising and tailgate dangerously, I found it best to pull over and let them go on their way. I've travelled Australia widely too but you don't say where you are going in that vast land. I'm guessing Sydney in which case you will probably have chance to see opera house, bridge, the rocks, botanic gardens, national museum and a ferry trip to Manly!