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: Headlight cleaner nozzle removal/installation
1. Remove the front bumper. (See FRONT BUMPER REMOVAL/INSTALLATION)
2. Disconnect the headlight cleaner hose. (See HEADLIGHT CLEANER HOSE
REMOVAL/INSTALLATION)
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
5. Adjust the headlight cleaner nozzle. ...
Mazda 6 Owners Manual: Excessive Speed Warning
If the vehicle speed exceeds the speed limit sign displayed on the active driving
display, the warning sound is activated and the area around the speed limit sign
displayed on the active driving display flashes 3 times in amber, and if the vehicle
speed continues to exceed the displayed speed ...