I guess it depends on how big your toddler is and of course how big your car seat it. The more "compact" ones I think your kiddy will grow out of sooner. I know that my DP has cheaper brand can seat in his car and Tehya's head is at the top, whereas in the safe and sound Royale she still has heaps of room until her head is at the top, and weight wise she will have ages, shes still only 12 kgs now, Noah who is 5 is only just 20kgs. So theorectically he could have only just came out of a carseat even though he's way to tall for one.

If you have a look on the NRMA website I think they have stuff on there about recommended carseats etc. Or google a few of the seat names we have given you on here that way you can see and compare them.