Read more: Iconic charity rally to hit Tauranga
"It's a fantastic experience and it's important to help take part in raising money for those who suffer from cancer.
"Everybody knows somebody who is affected by it," Mr Houston said.
"It's a great opportunity to do something great."
Mr Hallam said he had taken part in three other Australian rallies.
"It's great to see the different parts of a country, especially New Zealand, parts you wouldn't normally see in everyday life. It also great we can help raise money for such a fantastic cause."
Yesterday, the group of cars started in Opotiki and finished up the New Zealand leg of the race in Auckland. Last Friday they had been given different cars to choose from and then had one day to decorate them.
About 20 Kiwis had taken part in the experience too.