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: Smart Brake Support (SBS) (Some models)
The Smart Brake Support (SBS) system alerts the driver of a possible collision
using a display and warning sound if the radar sensor (front) and the Forward Sensing
Camera (FSC) determine that there is the possibility of a collision with a vehicle
ahead while the vehicle is being driven at abo ...
Mazda 6 Owners Manual: Front crossmember removal/installation
1. Remove the under cover.
2. Remove the splash shield.
3. Remove the front auto leveling sensor. (See FRONT AUTO LEVELING SENSOR
REMOVAL/INSTALLATION.)
4. Remove the transverse member. (See TRANSVERSE MEMBER
REMOVAL/INSTALLATION.)
5. Remove the steering gear and linkage, and pipe assembly i ...