Is it safer to install with the ISOFIX method or the lap sash method? Haris February 26, 2019 23:28 Updated Follow Both methods are equally as safe. Please follow the installation instructions in your child restraint's instruction manual. Related articles Will Mother's Choice car seats fit into my car? How do I know if my car seat is ISOFIX compatible? Can I use my overseas car seat in Australia? / Can I use my Australian child restraint overseas? Comments 0 comments Please sign in to leave a comment.