Mazda 3 Owner's Manual page 22

Front outboard seat
Rear outboard seat
*
Rear center seat
Removal/Installation
To remove the head restraint, pull it up
while pressing the stop-catch.
To install the head restraint, insert the legs
into the holes while pressing the stop-
catch.
WARNING
Always drive with the head restraints
installed when seats are being used and
make sure they are properly installed:
Driving with the head restraints not
installed is dangerous. With no support
behind your head, your neck could be
seriously injured in a collision.
Essential Safety Equipment
Seats
*Some models. 2–11