Mr Brownlee wants to make sure the 5.5 million warrant inspections a year, which cost car owners around $250 million in inspection fees, were justified.
However, Birchall and Maunder Automotive co-owner and Motor Trade Association board member Ross Birchall said New Zealand had many tight, twisty and dangerous roads and New Zealanders in general had poor driving habits leading to high failure rates in warrant checks.
"There are 3.2 million cars on the roads, 1.5 million of those are over 12 years old ... if people don't service their vehicles, who is going to take responsibility for them?"
He said warrant checks were a valuable part of his business.
"If we went to, say, 12-monthly checks the industry would lose about $100 million a year and guess who would end up unemployed? Jobs would go out the door," he said.
VTNZ Fenton Park manager Reg Monk said the failure rate for vehicles more than six years old was already high and if the Government knew the facts they would not change the system.
"But at this stage we don't know a lot about the changes," he said.
VTNZ assistant marketing manager Melanie Griggs said up to 30 per cent of all vehicles checked by the company failed their first inspection.
City Auto's service manager Mark Tremberth agreed that the 30 per cent failure rate was accurate.
"Especially for older vehicles ... with six monthly checks they often fail, but mostly for little things. If they drop [warrant checks] completely we will have a lot more unsafe cars on our roads," Mr Tremberth said.