All doors lock automatically when the lock side is pressed. They unlock when the unlock side is pressed.
Driver's door

Front passenger's door

To lock all the doors from an open front door, press the lock side of the door lock switch and then close the door.
NOTE
When locking the doors this way, be careful not to leave the key inside the vehicle.
Locking, Unlocking with Transmitter
Auto Lock/Unlock FunctionMazda 6 Owners Manual: Tiedown Hooks (Some models)
CAUTION
Do not use the front and rear tiedown eyelets for towing the vehicle. They
have been designed only for securing the vehicle to a transport vessel during shipping.
Using the eyelets for any other purpose could result in the vehicle being damaged.
Tiedown Hooks
1. Remove the tiedown eye ...
Mazda 6 Owners Manual: Smart City Brake Support (SCBS)
The Smart City Brake Support (SCBS) system alerts the driver of a possible collision
using an indication in the display and a warning sound when the Forward Sensing
Camera (FSC) detects a vehicle ahead and determines that a collision with a vehicle
ahead is unavoidable while the vehicle is bei ...