The boy was treated by paramedics on the side of the road before he was flown to The Children’s Hospital at Westmead in a critical condition. He died late on Tuesday.
The drivers of both the Mercedes and the BMW were not injured in the crash, and were taken to hospital for mandatory testing.
Assistant Commissioner Michael Corboy from Traffic and Highway Patrol Command said the boy’s injuries were «consistent with being struck by the airbag».
«The injuries to the child’s face, and the location of that child, and the fact that there was a proper restraint in the rear of that vehicle gives us an indication that there was a child on the lap of the driver of that car,» he said.
Officers from the crash investigation unit were still investigating the incident, and any witnesses who have not spoken to police yet or anyone with dashcam footage has been urged to contact police.