After much research we went for a Cosatto All-in-All Rotate which goes up to a theoretical 12 years old with extended rear facing if we choose to do that. Little one should still have at least another month and a half in his group 0+ seat but my wife is struggling to limbo his lanky frame under the roof of her Polo without donking his head so we decided to go for a spinning seat. Seemed a cheaper option than an SUV
Should be fitting it in this weekend.
We did have a slight wobble when we started reading bad reviews about Cosatto safety but despite my best efforts I couldn't see any reference beyond a particular seat that didn't rate that highly in ADAC and a whole load of Facebook and Mumsnet "expert" hyperbole.

We did have a slight wobble when we started reading bad reviews about Cosatto safety but despite my best efforts I couldn't see any reference beyond a particular seat that didn't rate that highly in ADAC and a whole load of Facebook and Mumsnet "expert" hyperbole.