8yo DD is approaching 140cm. Currently in a HBB we bought in Germany for children up to 150cm as per German regulations.
6yo DD is in a Joie Stages using the seatbelt. She is growing out of this.
We are undecided whether to move DD1 into a booster cushion, (she's not comfy with just a seatbelt yet despite apparently being tall enough in UK) or source another up to 150cm seat.
We do daily rural to urban journeys, plus long motorway drives at the weekend.