How does this affect the passenger behind the child?

Hi Melanie, thank you for your enquiry, the CARES harness should not affect the passenger behind, but I would check with the airline before travel to make sure of seat placement. We hope this helps. if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have. We hope this has helped with your query.