Driven around the Benz

A Finnish tourist snapped the Gullwing in action. Photo / Supplied

Mercedes-Benz' performance arm AMG has been secretly testing the modern-day version of the legendary 300SL Gullwing on roads in the South Island.

Finnish tourist Loof Lirpa spied the car in the rain in the Haast Pass heading towards the West Coast. "I'd been walking in the area and it sped past me while I was taking pictures from up on a hill," he said.

"You could hear it coming, the sound of the exhaust. But I couldn't see from where I was until the last second.

"It was the new Gullwing, for sure. The car people use Finland to test in the snow. We see new cars all the time, many covered in funny camouflage."

Lirpa said he drove his hire car back towards the coast hoping to catch up with the Gullwing, but it disappeared.

"It was as if it was never there," he said. "I even asked a petrol station if they had seen the car. They said I must have been dreaming.

"Then I showed them the picture in my digital camera. They were really surprised. One of the men was really excited and rang the phone.

"I couldn't stay - I had to meet friends from Finland in Queenstown. The only thing I saw that made me think after that was a truck and trailer with a container on the back. Maybe the Gullwing was inside the container."

Carmakers often use roads around the Deep South to test new cars. They fly them into Christchurch and truck them under cover to test venues like Queenstown's Snow Farm.

Mercedes-Benz admits it has been testing the new Gullwing in Europe, the United States, South Africa and Australia.

The car is officially called the SLS AMG and is powered by a 6.2-litre V8.

It is expected to be unveiled at the Frankfurt Motor Show in September. Right-hand-drive production for Britain, Japan, Australia, New Zealand and South Africa will begin on April 1 next year.