Fisher-Price 79050 Owner's Manual page 54

For a lap and shoulder belt system:
4B
With the vehicle belt buckled, pull the
vehicle shoulder belt just until the back
of the car seat begins to rise.
HINT
Some vehicle belt systems have labels
with instructions for use with car seats. Read
the instructions on your vehicle's belt or refer
to your vehicle owner's manual for specific
instructions on how to tighten and lock your
vehicle belt system.
Stay-in-View™ Infant Car Seat
52
Car Seat Installation without Base
4B