What should I do if the level line is not parallel to the ground when I install the car seat rear-facing?

If the level line is not parallel to the ground, you should disconnect the lower anchors or seat belt and place a tightly rolled towel or small blanket beneath the front edge of the child restraint to increase the recline angle. This is important because infants may have difficulty breathing when in an upright seated position. (Pages 28, 34)