A staffer's concerns have been revealed in documents released under the Official Information Act.
Niwa says a wide range of vehicles were test-driven but Chevrolet was the best option.
Northland man Chris Watson's dystopian-looking car was built in his shed in Kaiwaka.
"We've got things that are suited for the race track, things for the motorway, things for just the leisurely Sunday cruise."
The Clean Car Discount Scheme comes into force from the start of April.
Figures from the Motor Industry Association (MIA) show that 16,327 new vehicles were sold in November,
James Crow told RNZ on Monday he was shocked when he found out his new car's number plate featured the letters 'NGR'.
The display featured some of the most expensive supercars ever built.
"Anyone who was involved in this decision should be fired immediately."
