Medical experts are warning existing laws surrounding some child restraints are putting youngsters at risk.
They're concerned children are being moved out of booster seats before they're big enough, putting them in danger of serious injury and even death.
In NSW it's legal for seven-year-olds to move from a booster seat to an adult seat belt.
Trauma doctors said children are at significant risk if they are moved out of booster seats before they are 145 centimetres tall, which is a height most children reach at 10 or 12.
Trauma specialist Dr Warwick Teague said: "The sash part of the seat belt will rise up across the neck and that produces potentially life threatening injuries to the spine, the ligaments around the spine and the major blood vessels".
In the past year more than 4,500 drivers were fined for failing to correctly buckle up children.
Dimitra Vlahomitros, of the NRMA, said parents need to be vigilant because sometimes the less severe crashes can cause can cause more injuries.
"It's really important even if you're doing really short trips your kid is really buckled up correctly," Ms Vlahomitros said.
The importance of the restraints is something Ursula Garcia knows too well.
She was behind the wheel when her car flipped and said if her son Wade had not been in the seat he wouldn't have survived.
Luckily he was in the correct seat for his height and weight.