Oh my this is one of my most favorite topics to talk about. From correct installation to extended rear facing! In the US 6 out of every 10 deaths vehicle related deaths are due to improper carseat use.
Lets talk about rearfacing for a moment. According the the AAP it is recommended to rear face until 2 years of age. The law states 1 year and 20lbs which is hopefully going to be changing in 2012.
1.) A rear facing carseat is designed so that the carseat absorbs the shock of impact. When A child is forward facing
2.) A young infant/toddler's head is disproportionately large and heavy for their bodies, and their neck muscles are not completely developed. Due to those two facts, it is more likely that a child will 1. sustain a disabling or 2. life-threatening spinal cord injury when riding forward-facing instead of rear-facing in the event of a collision, or worse both!
3.) But their legs touch the seat!! Even though it looks uncomfortable it is actually more comfortable for children to ride rear facing. Why? It's rather simple because of the angle they are bent at when they just aren't quite tall enough to fold them at that 90 degree angle over the seat. Legs also have a higher tendency to get hurt in a forward facing accident versus a rearfacing child.
4.) Remember just because their legs are longer than the carseat (mainly pretaining to infant bucket seats) doesn't mean they have out grown their seat. Providing they still hit the weight requirements and their head is more than 1" away from the top of the shell then they are great! :)
I am to a extended harnessing advocate but that is a different discussion for a different day. I am going to go over some tips that are quite often forgot about before I leave you though.
winter coats winter coats are the worst thing possible when it comes to a carseat. Don't believe me then go strap your child in his seat with a winter coat on, pull the straps as tight as you can, then take the coat off and buckle him up.. What do you get? straps that are huge on him. When in a car accident the coat is often compressed and the slack well could be lethal if traveling fast enough. There are numerous ways to get around this. Carseat ponchos are great they are a lot like an "old lady" shawl but are now made out of uber cute fleece, some fleece can even keep kids warm 25 below 0. When it is super cold out how often does the car stay that cold? Mine I mostly heat up for them so the only time they are really getting cold is from the house to the car.
You can also remove the coat put them in their seat and put it on backwards. The second option is removing their arms, buckling them, then zipping them up.
third party products Head rests, seat protectors, toys, all these amazing things that attaching to you car seat... or so you think. Did you know if installed on most carseats these items will void warrenty and also propose a danger to your child. Some infant bucket seats come with supports and if they do are perfectly safe to use however if not manufacture made then these pose a danger. Thing such as hard plastic sunshades that go on the window can detach from the window and pose a risk. Infact a local police officer was telling me that he arrived at an accident where one of these devices actually impaled the child in the head and killed him. So be aware of what you are adding to seats.
expiration dates But car seats don't curdle right? Your right on that one but did you know that overtime plastic breaks down and micro-fractures occur, the fibers in the straps break down and can tear.
most of you know that carseat when involved in any accident need to be replaced. This is because of micro fractures in the seats, too much pressure on the straps, or even the harnessing system can cause failure if involved in a second accident.
washing your seat Refer to your users manual for this one but remember never ever use harsh chemicals on the straps of a seat, also never submerse them in water because this can cause the straps to break down or dry rot.
Remember to that not all firefighters or cops can answer your questions. They are not all certified to do so. Only 3 officers in my local state police are able to install seats. So you can call your local State police office and they will answer any questions as will your manufacturer of your seat.