DS is 2.2. He weighs 16.2kg and is 98cm tall. Very heavy and extremely tall for his age, but the normal proportions of a two year old, ie head in relation to body size etc, maybe a little on the skinny side. He's in a 5 point harness car seat but his head is now a good few inches above the top so today we went to Halfords and the man there said as his head was over the top, and his weight is over 15kg then he needs to go in to a high back booster with an adult belt. There are no high back boosters with 5 point harnesses that he knows of. This scares me. DS is just 2 - he will pull at an adult seat belt (I think) and I will be powerless to stop it, and he won't understand me saying why not. The seats barely recline (he still sleeps in the car often) and it just seems insane to me to put a just two year old in an adult belt? His head is still much larger in proportion to his body than a child 4+. So is that really my only option - to put him in a high back booster with adult belt? Am I being precious about it?