FORD 2013 Mustang v.1 - Manual (Page 145)

When raising the seatback(s), make sure you hear the seat latch into
place. Pull down on the seatback to ensure that it has latched.
WARNING: Before returning the seatback to its original position,
make sure that cargo or any objects are not trapped behind the
seatback. After returning the seatback to its original position, pull on
the seatback to ensure that it has fully latched. An unlatched seat may
become dangerous in the event of a sudden stop or collision.
Rear seat delete (if equipped)
WARNING: In a collision, passengers who are unbelted are
significantly more likely to be seriously injured or killed. Do not
allow people to ride in any area of your vehicle that is not equipped
with seats and safety belts. Be sure everyone in your vehicle is in a seat
and using a safety belt properly.
This is not a seating position.
Persons or child seats cannot be
placed in the rear of vehicles with
the rear seat delete option.
Seats 145
2013 05+ Mustang (197)
Owners Guide gf, 1st Printing
USA (fus)