Where do you think you are going? This isn't the Australian outback - restaurants, petrol, accomodation are in all the towns and the driving isn't a problem. My family did it in 1981 and it was like driving in country Victoria, only nicer.
Hix
Steph, Maddi and I have just done a 2 week NZ tour following some great advice from Chlidonias as to attractions to see.
Hix is right - very much like Victoria. Weather was perfect. Roadhouses, petrol stations, cafes everywhere but many close early and, most noticeably, the standard of service was quite slack - even in the touristy areas.
We hired a camper van and I would recommend doing so. We didn't have to worry about a timetable and there are camps everywhere of a high standard. Many of the motels in rural and regional areas were full by about 5pm so the van gave us independence. Compared with the cost of car hire, motel charges and higher food costs [you can prepare your own food in the van] the camper van was a cost effective option. The roads are good and well signed and driving anywhere was a breeze.
Highlights of the trip, apart from the warm welcomes everywhere from our colleagues, were: big, bold beautiful Takahe and Weka at Willowbank, free Giraffe and Rhino feeding at Orana Park, swimming with the tiny [you won't believe how small they are until you do it] Hector's dolphins at Akaroa, the wonderful improvements at Wellington Zoo [30 years since I was last there], a relaxed, prolonged view [as opposed to a glimpse!] of a Kiwi at Wellington Zoo, Pouakai Zoo's progressive march forward, Hamilton Zoo, more Weka here - this zoo is a gem, Auckland's Te Wao Nui and Ti Point Reptile Park - a must for reptile enthusiasts.
Disappointments - not many. We missed getting to Queenstown because our plane broke down in Brisbane, resulting in an eventual trip to Auckland before going on a day later to Christchurch to start the tour. The resulting loss of time also meant that we had to prioritise our objectives so some of the indigenous fauna attractions were dropped from the itinerary. We also missed the Albatross trip because of storms on the Kaikoura Coast.
We spent two very full weeks over there and could have easily spent another one. If you are a bit concerned about 'quakes in Christchurch I should mention that, on one of our nights there, the city experienced a 4.8 shock. In the campervan we didn't even feel it!