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: Blind Spot Monitoring (BSM) (Some models)
The Blind Spot Monitoring (BSM) is designed to assist the driver in checking
the area to the rear of the vehicle on both sides during lane changes by notifying
the driver of the presence of vehicles approaching from the rear in an adjacent
lane.
The Blind Spot Monitoring (BSM) detects vehicle ...
Mazda 6 Owners Manual: Pcm configuration
1. Connect the WDS to DLC-2.
2. Set up the WDS (including the vehicle recognition.)
3. Select Module programming.
4. Select Programmable module installation.
5. Select PCM and perform procedures according to directions on the WDS
screen.
Note
If PCM CONFIGURATION is successful, the PCM ...