Does anyone know the law on kid's car seats in Aus? We have a couple of booster seats that the kids use sometimes here in the UK. Kieran is 8 so that shouldn't be a problem in Australia. Daisy turns 5 at the end of April (we arrive mid March). Would a booster seat be ok for her or do we need to buy a more substantial seat once we are there? It would be great if we can simply bring their boosters over.