How do I properly install the Extend2Fit car seat in rear-facing position?

To install in rear-facing position, you can use either the LATCH system (for children 40 lb or less) or the vehicle seat belt. The car seat must be level with the bubble entirely under the blue lines (light blue line for infants 3 months and under). After installation, ensure the car seat moves less than 1 inch from side-to-side and front-to-back at the belt path. If using the vehicle seat belt and it doesn't hold the car seat securely, review the Vehicle Seat Belts section and your vehicle owner's manual.