If you ever find yourself in NZ and feel the need to wring the snot out of your rental car, there's few roads that can beat the Takaka Hill road in the top west of the South Island. It goes from sea level to 820 metres and back down to 110 metres in as the crow flies 15kms, so you gotta know it's twisty. The road eventually dead-ends at the village of Takaka, so there's not much traffic on the hill.
A bonus to the mighty blat is the Pupu Springs at Takaka, which has the second clearest fresh water in the world, with a underwater horizontal visibility of over 63 metres, a depth of 29 metres, and discharges 14,000 litres per second! Incidently, the clearest in the world is also in NZ.
We were over there to see the springs, etc about 10 years ago and had left our return too late and started the hill in the dark. From memory the missus and I had had a 'discussion' about something, so I attacked the hill, only to hit fog so thick we couldn't see more than two car lengths in front for the whole traverse. There was no-one else stupid enough to travel the hill, I was in a mood, I still had young eyes and did alot of night driving back then, so kept blasting over the hill. She says she will never travel on that hill with me ever again!
It's snowing here today in Glasgow, and when I skyped my mum in NZ the other night, she said it was so hot they were sleeping with just a sheet over them. Ho, hum