Can anyone recommend a car seat for our four-year old DS daughter, with the five-point harness usually provided for children up to 18 kg.  She is approaching the top of the weight range for her standard group 2 seat, but cannot be left to sit in the back of the car in a standard group 3 booster as she will not sit still.

 Any seat I have looked at is priced at £500 +.

Hi Bikerboy

This is very helpful indeed - thank you.