For your child's safety please read this and watch the videos.
We all know the laws about children and car seats…rear facing until 1 year and 20 lbs, and in some kind of car seat or boaster seat until the age of 8. However, that is only the minimum! There are reasons to keep your child facing backwards until they reach the weight limit of the seat and then stay in a 5-point harness until they reach the weight limit of that seat. There are some seats that go up to 80 lbs but you must read the label. You may see that the seat goes up to 100 lbs but that is not with the 5-point harness. The 2 seats that go up to 80 lbs are: the Radian80 ( http://www.skjp.com/products/skjp_radian_80.php ) and the Britax Regent ( http://www.britaxusa.com/products/product_detail.aspx?ID=9 ).