The new Nautilus 3-in-1 Car Seat is the only forward-facing car seat your child will need. Car Seat is the only forward-facing car seat your child will need. It helps keep him safe in a 5-point harness longer than most car seats, all the way up to 65 lbs. Later, the seat converts to a highback booster then backless booster, for comfortable, custom protection up to 100 lbs. Once your child outgrows her rear-facing infant car seat, she's still required ...