Video shows pair hang out of windows on Auckland's Southern Motorway

Horrified motorists could only watch as a car sped along Auckland's Southern Motorway with two of its occupants hanging out the windows, clutching cellphones and shooting videos.

The shocking footage was captured by a passenger in another car and shows two women sitting in the windows of the BMW, resting their arms on the roof as the car travels at 100km/h in the fast lane.

The video was shot on Saturday night at 6.30pm, with another eyewitness saying that the BMW joined the motorway at Papakura and the women hung out of the window the entire way, with the car exiting at nearby Takanini.

An eyewitness said the car was travelling at 100 km/h. Photo / Supplied

It shows the pair's faces illuminated by light from the screens as they use the devices to capture their reckless actions.

The eyewitness said he was shocked by their actions and said that all other cars gave the BMW a wide berth, with other drivers flashing their lights at the car as it weaved through traffic.

He said the car was travelling at 100km/h in the 80km/h zone, with the motorway busy with cars at the time.

"First they didn't have their cameras out, then they realised 'oh, I can put this on Instagram' so they took their cameras out and they were taking selfies, taking videos."

The pair appeared to use their phones to record video. Photo / Supplied

The video appears to show that the young women become aware that their actions have not gone unnoticed, with one pointing out to the other that they are being filmed.

A police spokesperson told the Herald that a police unit saw a vehicle matching this description in Otara on Saturday evening but by the time the officer attempted to follow the vehicle they had lost sight of it.

They said that police will be making enquiries into this footage which "clearly shows dangerous behaviour from some of the occupants in this vehicle on the motorway".

"Police do not tolerate reckless actions such as this on our roads and we encourage members of the public who witness this type of behaviour to contact us immediately at the time," the spokersperson added.