I have bought a Phil & Ted's navigator for ny newborn and 18 month old, however now I have started using it I am a bit confused. I have laid my newborn down in the unzipped main seat and put my toddler on top but if I put the sunhood up there is a massive gape at the back exposing my newborn and giving no protection against the wind and rain. Is there something you can buy to fix over that? Also when can I put my newborn in the second seat? It says 6 months but can I do it any earlier? and should I get a footmuff to make them more comfy? I am starting to regret buying this as there seems to be a few flaws when catering for a newborn