"When I wake up every day I try to be positive. I use my positive thinking to try and keep me fit," Cunningham said.
"Once you end up in a wheelchair it gets easy because people push you everywhere, you don't have to do anything. But you've got to push yourself. I think that's the Kiwi and the Aussie way: never give up.
"I'm very lucky because I've got the slow progressing disease. Two years ago, when I first got really ill, I didn't think I'd get to 50."
Cunningham started driving go-karts as a 10-year-old in Mt Wellington, Auckland.
His family later moved to the Gold Coast.
"That's where my career started blossoming. As I got older I used to get chased by the Queensland police."
One night he was caught by an officer who introduced him to a racing driver. Police officers later watched his first qualifying race as an 18-year-old.
Three-time world F1 champion Sir Jack Brabham took Cunningham to Britain, where he raced the European circuit with the Australian team.
A fellow driver put Cunningham on to Top Gear, but he denies rumours he was ever the on-screen Stig - the white-suited test driver whose identity was a closely guarded secret: "I always had the Stig in my mirror," he said.
Cunningham was a stunt driver for Top Gear Live before his big-screen breakthrough when he was recruited for the Bond film in 2008.
Few people knew about his diagnosis of motor neuron disease late in 2010 and he continued to race until last September.
Mr Cunningham says his London doctor, New Zealand-born Professor Christopher Shaw, keeps his hopes high for a cure to the disease.
He has become a campaigner for awareness about the disease and helped raise about £55,000 ($110,000) for Professor Shaw's research.
Close friend James Beckett said there was large network of loyal friends banded around Cunningham and his family.
"There really isn't a nicer person in British motorsport and people tell him that all the time," Mr Beckett said.
Cunningham lives with his Welsh wife, Rachael, and his daughter India-Bo, 4, and son Ted, 2, in Swansea, Wales, where he has planted native New Zealand ferns to cure his homesickness. He also has another daughter, Jaime, 23.
He plans to return to his Kiwi roots and live at Mt Maunganui.
"I will get better," he said. "I want to go back to racing cars. I'm going to return to New Zealand and go sit on the beach with my kids. That's the plan."