Car seats are designed to save young lives. Unfortunately, most parents think they are installing the seats correctly, when inspections show seven in 10 are installed wrong! The consequences can be deadly given that motor vehicle accidents are the number one killer of kids in this country. And in fact, the Centers for Disease Control and Prevention estimates that more than half of those deaths and serious injuries could be prevented by placing children in age- and size-appropriate car and booster seats. "Child safety seats save hundreds of young lives every year, but proper use is vital," said David Strickland, administrator at the National Highway Safety and Traffic Administration (NHSTA). "That's why we're urging everyone to make sure their kids are properly protected on every trip, every time." Avoid These Common Mistakes Mistake #1: Seat too loose Test it: Grab the car seat at its base, near where the safety belt passes through. If you can move it more than one inch to the left, right or forward, it's too loose. The danger: In a collision, a child in a loose seat could crash into the front seat and suffer serious head and face injuries. Fast fix: Read the manual first (only 20 percent of parents do, according to a recent survey by the NHSTA). Add your weight and tighten the seat belt as much as possible. For forward-facing seats, also use the top tether to help lock the seat in place. Mistake #2: Harness too loose Test it: Once the child is in the car seat, pinch the harness at the shoulder with the chest clip properly in place. If you're unable to pinch any excess webbing, it's tight enough. The danger: A child can easily slip out of a loose harness or even be ejected from the vehicle, suffering severe injuries. Fast fix: Always use the chest clip, and position it level with the armpit. Make sure the harness passes through the proper slots and is tightly buckled. There should be no slack. Mistake #3: Infant turned face forward too soon Test it: According to the American Academy of Pediatrics, all children should remain rear facing at least until they turn 2 years old or have reached the maximum height or weight capacity of the infant car seat. Inspections show that 30 percent of infants are turned around too soon. The danger: An infant's bones and spinal cord are still forming. When a child is rear facing, the strongest part of her body - the back - can better absorb the immense forces of a crash. When facing forward, an infant's relatively heavy head can catapult, putting pressure on the undeveloped spine and risking paralysis or death. Fast fix: Read the seat label and follow age and height/weight limits. Mistake #4: Rear-facing infant seat not at a 45-degree angle Test it: Many infant car seats have a built-in level that tells you when your seat is at the wrong angle. More often than not, seats are installed in a position that's too upright. The danger: An infant's airway is as narrow as the diameter of a soda straw. If a rear-facing seat leans too far forward, the baby's head can fall forward, cutting off her airway. Fast fix: If your safety seat is not equipped with an adjustable pedestal to ensure the correct angle, tightly rolled up towels or a section of a swimming-pool noodle can be placed under the area where a baby's feet rest. Mistake #5: Not knowing the age stages Test it: Any child between 40 and 80 pounds and up to 4'9" tall (generally kids from 4 to 8 years old) needs a booster seat. And children under 13 should never sit in the front seat. The danger: An adult seat belt doesn't properly restrain a child because it crosses the body at the wrong position: too high on the belly and across the shoulder. Plus, children often move the shoulder belt behind them because it's uncomfortable. During a crash, a child who is too small for a seat belt can sustain internal, head or spinal injuries. Fast fix: Move older children to a booster seat when they reach the height or weight limit allowed by the car seat manufacturer. Here's a handy guide for choosing the right seat. For more details, download this safety checklist and keep it in your vehicle. If you have ANY doubt whatsoever about the proper selection or installation of your child or booster seat, find a child passenger safety technician or checkup station near you. A child's life is at stake!