Graco stamps an expiration date into the bottom of each car seat so you know when it is time to replace it. Expiration dates can range anywhere from six to ten years or more depending on the car seat – so it’s important to check your particular seat.Used or expired car seats can be dangerous, especially if you don’t know the car seat’s history. For more information on how to find the age of your car seat, click here. Children should ride rear-facing in a car seat up to two years old. 2  Children should sit in a booster seat until they are 4’9”. 3  For more information on the new recommendations, visit www.AAP.org.