A man who was stabbed several times during a fight between the two groups in the Sydney West at 3am, is in a hospital under surgery.
The fighting between groups on the Paradi soldiers, Edmondson Park, was triggered before more people arrived in the third vehicle and joined, the police said.
Range Rover has allegedly accelerated Toiota Tarago before driving.
The man who was stabbed suffered a collapsed lung and was taken to the Liverpool hospital in an unknown state.
Two others suffered minor injuries.
There were no arrests, but officers established a crime scene and interviewed witnesses.