Yes | No Thank you! That is way too old for a carseat. The average length of time that a car seat is good for is 6 years. Only a few companies make seats that will last longer than that. There is a really good video of what happens in a crash whaen an old car seat is used onthe car seat safety board.hat is way too old for a carseat. The average length of time that a car seat is good for is 6 years. Only a few companies make seats that will last longer than that.