I have just realised that 3yr old DD is 18.8 kg and too big for her Britax seat.
The only shops I can get to before we do a long motorway journey tomorrow are Argos, Halfords or Smyths which stock both seats above or Obaby ones or Joie hbb under £100.
Alternatively I could put her in a 6yr old Maxi Cosi Rodi previously owned by her brother ( if indeed her brother should be out of a hbb at all, he's over the height restriction but under the weight one).
Any advice would be v welcome as I'm going around in circles!