My son is now 3 years old, he weighs 16kg and is quite tall for his age. He is looking quite big in the car seat he is in at the minute. I was looking at getting him a new car seat (a booster one with the back) but I'm so confused by the law because it says for that type of seat age 4-12 but then says about the weight too. I just wondered if there are any others out there with some advice or guidance. Thanks in advance!