The rear armrest in the center of the rear seatback can be used (no occupant in the center seat) or placed upright.

WARNING
Never put your hands and fingers around the moving parts of the seat and armrest:
Putting your hands and fingers around the moving parts of the seat and armrest is dangerous as they could get injured.
Split Folding
Head RestraintsMazda 6 Owners Manual: i-ACTIVSENSE (Some models)
i-ACTIVSENSE is a collective term covering a series of advanced safety and driver
support systems which make use of a Forward Sensing Camera (FSC) and radar sensors.
These systems consist of active safety and pre-crash safety systems.
These systems are designed to assist the driver in safer dri ...
Mazda 6 Owners Manual: Anchor Bracket
Anchor brackets for securing childrestraint systems are equipped in the vehicle.
Locate each anchor position using the illustration.
To install a child-restraint system, remove the head restraint. Always follow
the instruction manual accompanying the child-restraint system.
Anchor bracket loca ...