Car Seat Safety: Install It Right and Know When to Move Up
Keep each child in the current restraint stage until the seat's height or weight limit is reached, then confirm the next restraint fits both the child and the vehicle.
Quick answer
Install every child restraint in the back seat and follow both manuals. Keep children rear-facing until they outgrow that seat's rear-facing limit, then use a forward-facing harness with its top tether, then a belt-positioning booster until the vehicle belt fits correctly. Children should remain in the back seat through age 12.
The four stages
Rear-facing car seat
Keep the child rear-facing as long as possible, until reaching the seat maker's height or weight limit.
Forward-facing harness
Use the harness until its limit and attach the top tether as directed.
Belt-positioning booster
Use a lap-and-shoulder belt with the lap portion low on the upper thighs and shoulder portion across the chest.
Vehicle seat belt
Move out of a booster only when the belt fits correctly and the child can maintain that position for the whole trip.