There are so many, I am completely confused! My son is nearly two but still in his rear facing from birth car seat as he is small and still only 80cm so his head is still not above the back. However, it is getting close now and it is time to get the next one up. We did consider extended rear facing but I think that they are too long for our car. Then I have the option of now-4 years, or now -12 years. Surely the latter makes sense, is there a reason that you would choose the In between one and get two instead of one. We have isofix in our car and would like to use it but it seems to bump up the price, is there a big safety difference? Any recommendations please?