My 3 year old has outgrown his stage 1 car seat, his head is above the back rest; I bought him a Joie Trillo Shield for my husband's car, but he will not have the shield on & so I use it in stage 2/3 mode with the seat belt. He is above the height & weight lower limits (just). I need to get another seat for him for my car, which he travels in a lot more. His sister has a Britax Kidfix, which was much more expensive than the Trillo LXs, but doesn't look as comfy. Does anyone have any recommendations? Thanks