A search is underway for a man filmed launching a road rage attack on a car in Brisbane's south-west.

Mobile phone footage shows a dark blue van and light blue car swerving and changing lanes on Blunder Road in Durack, before they come to a stop in a turning lane.

A man then runs out of the Volkswagen van and punches and kicks the front and side of the car, before it drives off.

Witness Gary Davey said the behaviour was "intolerable".

"Quite a bit of coming together, they were swapping lanes, chasing each other, then the guy in the blue car then hurled a bottle of water out into the guy in the car in front, and I thought 'wow, that's insane'," he said.

"[I] watched him get out, belted the car, kicked it, and… the other guy was able to escape.

"Just insane unacceptable behaviour, just intolerable in our society I believe."