Final answer:
Children should be in a rear-facing car seat from age 0 to approximately 2.5 years, or until they reach the maximum weight or height limit set by the car seat's manufacturer.
Step-by-step explanation:
The age and weight requirements for a rear-facing car seat typically dictate that children ages 0 to 2.5 years or until they exceed the weight or height limit set by the car seat manufacturer, should be in a rear-facing car seat. As children grow significantly during their first years, weight and height are more relevant factors than age alone. This requirement is crucial for safeguarding the children's safety, as rear-facing seats protect a child's head, neck, and spine much more effectively in the event of a collision. This aligns with safety recommendations by experts, who emphasize the importance of using car seats properly to ensure children's safety on the road.