I didn't think it was that you had to turn them once they reach the line, just that you can't turn them beforehand. DS has been in a the Meridian AHR and we only just turned him at nearly 12 months although he's been over the line (although still fitting in the chair in rear-facing mode) for months.
ETA: RACV explains it (for Victoria anyway):
The rules require that:
Children aged under 6 months must use an approved, properly fastened and adjusted rearward facing restraint.
Children aged between 6 months and under 4 years must use an approved, properly fastened and adjusted rearward facing child restraint OR a forward facing restraint.
Children aged between 4 years and under 7 years must use an approved, properly fastened and adjusted forward facing restraint OR an approved booster seat which is properly positioned and fastened.
What can I do if my child is too big for the restraint for their age?
The laws aim to cater for the majority of children, however there is a provision to allow a child who is too heavy or tall for the recommended restraint to use the restraint in the next age category.
This post has been edited by Joey11: 18/02/2013, 04:01 PM