Lucky bugger!
I was over in NZ last March for a few weeks...It's a fantastic place, and I'd love to return...
I was staying with my mate & his wife in Christchurch, but borrowed his car for a week and headed around the south island with some other friends who were also over at the time...
I can recommend:
Arthurs Pass National Park
Franz Josef / Fox Glacier - We went horse riding around here for not a lot of £££, and it was great...
Wanaka - Beautiful little town
The Crowne pass - Road to Queenstown...I wore out the brake pads in my borrowed A4 driving up and down this...
Queenstown - Great for drinking, and all the adventure stuff like bungee, sky diving, jet boat, rafting etc...
Christchurch itself is a hoot - Although I was mainly out drinking at night, so didn't see it during the day...
Akoroa (sp?) - You can see the whales / dolphins etc...Or go fishing instead, like we did on a chartered boat...
There's heaps to see and do...I didn't scratch the surface...I hear Millford Sound / Dunedin / Invercargill / Hammner Springs are all worth a look...There is a bit of a well worn tourist trail, clockwise around the south island...Most guidebooks will keep you right...
As for petrolhead activities - There's Ruapuna circuit in Christchurch...I did a driver day there in an RX7 and FF1600...No rev limits, or restrictions like KH experience days...Great fun, and not too expensive given the exchange rate at the time...(The guy who runs it is like a kiwi walshy...

)
You'll have a blast - I'm very jealous!
