There is another type of car seat called booster seats but it is important to distinguish them from car seats that are built for babies. (mommyedition.com)
This can be especially effective for all - in - two diapers, but also works well for pockets, and even for boosters for all - in - ones! (thinking-about-cloth-diapers.com)
They should sit in booster seats until they're at least 8 years old. (stanfordchildrens.org)