2012 Toyota Prius Owners Manual - Page 452

1-8. Safety information STEP 2 Run the seat belt through the child restraint system and insert the plate into the buckle. Make sure that the belt is not twisted. 1 Before driving STEP 3 Fully extend the shoulder belt and allow it to retract to put it in lock mode. In lock mode, the belt cannot be extended. STEP 4 While pushing the child restraint system down into the rear seat, allow the shoulder belt to retract until the child restraint system is securely in place. After the shoulder belt has retracted to a point where there is no slack in the belt, pull the belt to check that it cannot be extended. 141