This photo shows the RIGHT WAY to put your child in their car seat.
The next problem I see is with the straps themselves. People think that their child will be uncomfortable if the straps are tight. Better uncomfortable than dead, in my opinion. Straps need to be flat against the child's body, with just enough room under the strap for ONE finger. If you have any slack in the strapping, your child is NOT safe. Tighten, check, tighten, check... They need to lay flat on the child and not be twisted. Besides keeping your child from being ejected from their car seat, it also helps keep them sitting in it!!!