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: No.1 while vehicle is in reverse, vehicle locator mark goes forward
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connectors, terminals and wiri ...
Mazda 6 Owners Manual: Accessory Sockets
Only use genuine Mazda accessories or the equivalent requiring no greater than
120 W (DC 12 V, 10 A).
Front
The ignition must be switched to ACC or ON.
Center
The accessory sockets can be used regardless of whether the ignition is on or
off.
CAUTION
To prevent accessory socket damag ...