Ds has a hipod. Its made with places for the seat belt to tuck into so its not too high on his neck or tummy. Also has the tether/anchor.
I can't remember what age it goes to though. He's 6 & not a tiny 6. I don't think there'd much point buying another one now... hopefully I won't have too.

Dd has a 6m-8y. If I'm lucky I'll stretch it out til she's 10. Wish they'd started making them earlier.