Toyota Prius C 2011 Owner's Manual page 113

1-8. Safety information
Installing child restraints using a seat belt (child restraint lock function belt)
Rear facing  Baby seat (Infant seat)/child seat (Convertible
■
seat)
STEP 1
STEP 2
112
Child restraint anchor fitting
An anchor fitting is provided for
each rear seat.
Place the child restraint system
on the rear seat facing the rear
of the vehicle.
Run the seat belt through the
child restraint system and insert
the plate into the buckle. Make
sure that the belt is not twisted.