Three out of Four Car Seats are Installed Incorrectly.

Three out of four car seats are installed incorrectly.

You need to become an expert at this, so read your car seat and vehicle manuals thoroughly, take a class if possible, and have your installation inspected by a professional. "Knowing how to install your baby's car seat is of paramount importance," Shu says. Read our expert tips on Which Car Seat, When? in the 2008 Buyer's Guide.

This is how to properly install a rear-facing car seat:

1. Install the Base

Place the base in the center of the backseat and thread the seat belt through the guides. Kneel on the base as you tighten the belt; make sure the base cannot move more than 1 inch in any direction.

2. Put the Baby in the Seat

Place your child in the car seat and secure the harness; make sure the harness is snug against your baby's hips and shoulders. Adjust the chest clip so it's level with your baby's armpits.

3. Put the Seat in the Car

Place the car seat in the base, making sure it snaps in securely. Flip the handle down and lock it into place; this will prevent it from harming your baby in case of an accident.

4. Check The Angle

The seat must be installed at an angle that keeps your baby in a semi-reclined position; his head must not be able to flop. Place a rolled-up towel under the base to get the right angle, if needed.

Read more about car seat safety at And be sure to take our Baby Safety Quiz.