Hi Milly
Only just logged on here for the first time to find you say you've decided not to do any organised coach tour in NZ - if it's not too late and you're going to be in Nelson or Queenstown soon, then get yourself on the West Coast Express...more fun than you can shake a stick at with the chance to see the glaciers/bungy jump etc for a ridiculously cheap price.
OK, so you can see the road through the floor of the bus but what's a little natural air-conditioning when you won't want to go to sleep at night because you're having such a good time?!
NZ is a special place - have fun there.