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: Liftgate disassembly/assembly
1. Disconnect the negative battery cable.
2. Remove the liftgate lower trim.
3. To remove the liftgate outer handle and liftgate key cylinder, remove the
rear finisher.
4. To remove the stud ball, separate the stud ball and the stay damper.
5. Disassemble in the order indicated in the table.
...
Mazda 6 Owners Manual: Units
Conversion to SI Units (Système International d'Unités)
All numerical values in this manual are based on SI units. Numbers shown
in conventional units are converted from these values.
Rounding Off
Converted values are rounded off to the same number of places as the SI
unit value ...