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: Climate control unit removal
1. Disconnect the negative battery cable.
2. Disconnect the air mix and airflow mode wires from each wire clamp and
link. (Manual air conditioner)
3. Remove the center panel. (See CENTER PANEL MODULE REMOVAL/INSTALLATION.)
4. Remove the screws and climate control unit. (Full-auto air conditione ...
Mazda 6 Owners Manual: No.9 noise while operating a/c system
Diagnostic procedure
* : If there is gas leakage, air enters into the A/C system. The desiccant
within the receiver/drier absorbs the moisture from the air and becomes
saturated. If the A/C system is used in this condition, the inside of the A/C
compressor will begin to rust due to this ...