We are now right in the middle of National Child Passenger Safety Week and I came across this great article which has some tips about child car seats that aren't normally included in other articles. It is highly recommended to read the car seat user manual thoroughly in order to see what is accepted or not, since every manufacturer has different directions. Do you know if the carrying handle is allowed to be kept up while the safety seat is secured in the car? With some models this is okay but with others the baby may hit the handle in a car accident or it may break into pieces.
That being said, not all models are allowed to touch the back of the seat in front of it, known as 'bracing.' For instance, Evenflo seats are not supposed to do those though it's okay with other models. Regardless of the model, you must make sure that the harness straps are not twisted. A twist in the strap can make for a weak point and in the event of an accident, the force of the impact may not be distributed evenly which can cause injuries.
As a personal injury lawyer in South Carolina , I urge you to familiarize yourself with the tethers and anchors in your car. The tether on the top, back portion of the car seat should be used on all forward facing and even some rear-facing seats in order to minimize movement in an accident. In Canada, it's actually illegal not to use this tether, according to this article. If your car doesn't have a good anchor, you can have one put in at the dealership for a very minimal cost.