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: Cup Holder
WARNING
Never use a cup holder to hold hot liquids while the vehicle is moving:
Using a cup holder to hold hot liquids while the vehicle is moving is dangerous.
If the contents spill, you could be scalded.
Do not put anything other than cups or drink cans in cup holders:
Putting objects othe ...
Mazda 6 Owners Manual: Gracenote Database
When a USB device is connected to this unit and the audio is played, the album
name, artist name, genre and title information are automatically displayed if there
is a match in the vehicle's database compilation to the music being played. The
information stored in this device uses database inf ...