Did you know two in three child car seats are not being used correctly, increasing the risk of serious injury?

So make sure you do the "1, 2, 3, They're counting on you."

The Wiggles, with Transport for New South Wales, are helping little passengers stay safe. When buckling up your car seat there are three easy steps to follow to help keep your children safe.

Research by the Child Restraint Evaluation Program (CREP) revealed children who are restrained incorrectly are up to seven times more likely to be seriously injured in a crash than children who are in the correct car seat for their age and size.

Always follow the manufacturer's instructions carefully when fitting a child car seat and placing your child in it. If the instructions have been lost, contact the manufacturer, search for the instructions online, or seek advice from specialist Authorised Restraint Fitters.

Adjust the inbuilt harness for a comfortable but firm fit, with no slack. The harness straps should be straight and in flat contact with the child. Double check the harness straps are not twisted or caught.

In booster seats, make sure the sash belt crosses your child's shoulder and is in contact with the chest. Make sure the lap belt sits low across the pelvis (hip bones).

Common issues an Authorised Restraint Fitter will look for and fix include:

Remember your little passengers are counting on you to keep them safe by ensuring they have the right child car seat, being used correctly.

Ask yourself: have you got the right car seat, have you fitted and adjusted it correctly and do you know how to check it properly?

Go to www.childcarseats.com.au for more information. It provides advice for choosing the safest option by comparing price, safety ratings and ease of use of a range of child car seats tested by CREP and links to Authorised Restraint Fitters in your area.