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: Traffic Sign Recognition System (TSR) (Some models)
The Traffic Sign Recognition System (TSR) helps prevent the driver from overlooking
traffic signs, and provides support for safer driving by displaying traffic signs
on the active driving display which are recognized by the Forward Sensing Camera
(FSC) or recorded in the navigation system whil ...
Mazda 6 Owners Manual: General procedures
PRECAUTION (CLUTCH)
Clutch Pipe Removal/Installation
Note
A common reservoir is used for the clutch and brake system fluid.
1. If clutch pipes have been disconnected any time during the procedure, add
clutch fluid (brake fluid), bleed the air, and inspect for leakage after the
procedure ...