Police Inspector Karl Wright-St Clair, area prevention manager for Western Bay of Plenty, said staff were "extremely disappointed to see an example of such stupid and dangerous behaviour".
Further inquiries into the incident were under way and anyone who witnessed it, as well as those who filmed it, should contact police, he said.
The behaviour in the video showed an "obvious lack of regard for personal safety" and put other innocent motorists at risk, Mr Wright-St Clair said.
"If proven, this may result in prosecution of both the vehicle driver and the person 'surfing' for dangerous driving," he said. "While instances of 'car surfing' are not common, there is no place for this type of mindless behaviour on our roads."
The Automobile Association's road safety spokesman Mike Noon said the activity "is obviously incredibly dangerous and a stupid thing to do".
Two years ago, a Wellington teenager was critically injured when he fell from a moving vehicle while car surfing in Upper Hutt.
The teen suffered serious head injuries.
Further south, Mosgiel resident Nick Vermeulen suffered serious injuries the same year in a car surfing accident.
Mr Vermeulen had been drinking and fell off the vehicle when it turned a corner.
He fractured his skull, broke his collarbone and four ribs.
In 2010, a 26-year-old woman was critically injured when she fell from the roof of a vehicle in New Plymouth.
By last night, the video had more than 70 views on YouTube.
