The Counties Manukau serious crash unit was investigating, but said yesterday that it was too soon to comment. Police would not be drawn on the details of the crash, including how many cars were involved and who else was in the vehicle with the baby.
The crash came days before Transport Minister Steven Joyce and child safety advocacy group Safekids are scheduled to launch a website about the dangers of incorrect car-seat installation.
The site will be officially launched on Wednesday and aims to provide parents with important information about how to choose the right car seat for their car, and their child.
The law in New Zealand requires drivers to have all children aged under 5 in a child car restraint for every ride. Safekids director Ann Weaver said the 14-day-old's injuries were "very sad".
According to the Government's road safety strategy to 2020, New Zealand has one of the highest rates of child road deaths in the world and Mrs Weaver said part of that was due to the lack of or incorrect use of appropriate restraints.
"Incorrect installation can greatly reduce the safety benefits of a child car seat."
Mrs Weaver said international research showed four out of five child car seats were incorrectly fitted.
Latest figures released by Safekids, established in the 1990s by the Starship to help reduce the high rates of preventable injury to children under 15, show that car restraints reduce the risk of death for infants by up to 70 per cent.
They reduce the risk of death to toddlers by up to 54 per cent, and decrease the need for hospitalisation for children under 4 years old by up to 65 per cent.
"I think it's really important for parents to learn how to install their car seats correctly. They are so complicated, it's not an easy thing," said Mrs Weaver. "People think it's simple to put a seat into your car, but it's not like that. You have to get the right fit for the right child for the right car.
"It's particularly important for new parents to get their seats checked and to have someone talk them through the process of putting in the baby capsule."
She said car seats and capsules could be rented from Plunket, which would also install them correctly.
People could also go to a New Zealand Transport Agency-approved certified child restraint technician to get the job done correctly.
Buckle them in
* Latest figures released by Safekids show that car restraints reduce the risk of death for infants by up to 70 per cent.
* They reduce the risk of death to toddlers by up to 54 per cent, and decrease the need for hospital treatment for children under 4 years old by up to 65 per cent.
* The law requires all children under 5 years old to be restrained in a child car restraint for every ride.
