Install your Car Seat with a Lap Belt
Check the car owner’s manual to find out how to use a lap belt with an infant car seat in your car.
Put the seat belt through the marked pathway on the infant car seat or base and buckle the seat belt.
Push down on the infant car seat or base and pull seat belt tight. You can also use your knee to push the base or car seat into the car.
Test the seat belt to be sure it is locked in place and can’t move. If the seat belt moves, unbuckle the seatbelt, flip the buckle over and buckle it again.
Check to see that the car seat or base is tight at the spot that it is anchored to in the car. Place your hands on each side of the base, and try to move the car seat or base side to side and front to back. The car seat or base should not move more than one inch (2.5 cm) side to side or front to back. If the base moves too much, push down on the base hard and pull the belt tighter.
For the rear-facing seats, it is okay to have movement at the top of the seat (where your baby’s head is). This is called rebounding and rear-facing car seats are designed to do this, but the care seat base should not move more than one inch (2.5 cm) where it is anchored to the car.
If you are using a seat belt do not also use the UAS/Latch system.