Sounds to me like your missing the seatbelt gripper that comes with the child seat...this keeps the seatbelt in a "locked" position...most of the time its in a holder on the bottom of the seat...better yet...take it to the fire dept. and let them do it...center of the car is better for a rear facing seat anyhow...a pain in the *** but safer...and the fire dept. will do it for free, have any recall notices for your model car seat, and put you on record in case their is an accident an ambulance is automatically rolled...just let them do it...