I have been reading about carseat safety, as I have been trying to figure out what will be my next carseat purchase, in anticipation that Danielle will soon outgrow her infant seat. I have always been of big advocate of infants riding rear-facing until they are at least one year of age and at least 20 pounds. But as soon as they hit that mark, it has been somewhat of a milestone to turn them forward-facing. However, I will not be doing that this time.
"The American Academy of Pediatrics (AAP) recommends that all infants should ride rear-facing starting with their first ride home from the hospital. They should remain rear-facing until they reach the highest weight or height allowed by their car safety seat’s manufacturer. At a minimum, children should ride rear-facing until they have reached at least 1 year of age and weigh at least 20 pounds."
I now realize that the 1 year, 20 pound rule is a minimum. When we move from rear-facing to froward facing, it is a step down in terms of safety. So when Danielle moves to her next carseat which will be a Britax Marathon, she will be able to ride rear-facing as long is she is under 35 pounds, and 49", it also has a seated shoulder height limit of 16".

Both Brian and Emily have been a Britax Marathon since they moved from the infant carseat. They were rear-facing until they met the minimum standard, and then we ceremoniously turned them around. I love the Britax seats, they are comfortable, easy to use, and safe. The Marthon will accommodate a child forward-facing to 65 pounds, 49", and a seated shoulder height of 16".
So Brian still fits in his marathon for now, he weighs 44lbs, and is 42" tall. I will give his seat to Danielle, and buy him the new Britax Frontier. Danielle will be able to use his seat until it expires (which is 6 years from the manufactures date).
The Britax Frontier is a combination Harness-2-Booster seat. This means it will be the last seat I will have to buy for Brian. He can continue to be in a 5-point harness with this seat to 80 pounds, and 53", with a seated shoulder height of 18.25".
Remember a 5 point harness is the safest for your child. The step up to the booster, is actually a step down in safety. A 5-point harness restricts movement, which ensures that the child is in the proper position should a crash occur, and it also distributes the crash forces over a larger area of the body when compared to a safety belt and booster. Therefore, a child should be mature enough to sit in a booster seat properly; not slumping, reaching for a dropped toy, etc.
Can you spot the Safety Violation?
This from the AAP: "Once your child has reached the highest weight or height allowed by the manufacturer of the seat for rear-facing, she can ride forward-facing in a convertible seat. However, it is best for her to ride rear-facing to the highest weight or height allowed by the manufacturer of her car safety seat. She should ride in a forward-facing seat with a harness until she outgrows it (usually at around 4 years of age and about 40–65 pounds)."
Then, the Frontier will convert to a booster seat to a maximum weight of 100 pounds, and 60" with a seated shoulder height of 21.5".
From the AAP: Booster seats are for older children who have outgrown their forward-facing car safety seats. It is best for children to ride in a harnessed seat as long as possible, at least to 4 years of age. If your child outgrows his seat before reaching 4 years of age, consider using a seat with a harness approved for higher weights and heights.
Don't let the advertising on the box guide your decision!
So to recap...
Keep your infant in the safest position possible, rear-facing until 35 pounds.
Keep your toddler in the safest position possible, rear-facing until 35 pounds
Keep your child in the safest seat, a five-point harness until at least 4 years of age (40-65 pounds). The Frontier goes to 80 pounds.
Move your child to a booster seat when they have outgrown the safety seat.
Children under 12 should never ride in the front seat.
From the AAP: Seat belts are made for adults. Your child should stay in a booster seat until adult seat belts fit correctly (usually when the child reaches about 4' 9" in height and is between 8 and 12 years of age).
Please do your research and consider taking a step back to a child safety seat for your child.