A video posted on Facebook page Dash Cam Owners Australia shows a man riding on the back of a black sedan, holding onto the roof with both hands and using the rear spoiler to steady himself.

The car, which appears to be travelling on Carrick Drive, Tullamarine, goes over two speed bumps and slows as another car turns in front of it during the short video, The Weekly Review reports.

Passengers in the car behind can be heard commenting as one of them filmed the incident.

"If he falls off, I'm going to run him over," the driver says.

One passenger repeatedly warns the driver to "keep your distance".

The video, posted about 11am on Tuesday, had more than 70,000 views in three hours, as well as 1000 likes, more than 200 shares and 400 comments.

The original post said: "When you need to get all your mates to the bottle-o on Australia Day … Melbourne, Victoria. Thanks to Mario".

Some Facebook comments on the post praised the man riding on the car. But many labelled his actions irresponsible and dangerous.

"Obviously the message is not getting through to some people. Not only are they risking their own lives, but what if someone had fallen off and been run over?" one comment said.

Victoria Police media officer Creina O'Grady said there was no excuse for the behaviour shown in the video.

"The driver of this car has not only put the life of the man clinging onto the roof of his vehicle at risk, he is also risking the lives of other road users," Ms O'Grady said. "Safe driving and surviving on our roads is a complex task and requires the full concentration of all road users, drivers, passengers and pedestrians."

Ms O'Grady said several people had reported "these types of incidents" recently.

"However, we also don't want people putting themselves at risk to take photographs of other drivers doing the wrong thing. Take details where you can and report it to police, and contact triple zero if you believe there is immediate danger," she said.

A spokesman for Dash Cam Owners Australia said the page did not condone such risky behaviour.

A spokesman for Dash Cam Owners Australia said: "while the persons involved seem to think it is funny, it could easily result in another needless death on our roads".

The Weekly Review