These locks are intended to help prevent children from accidentally opening the rear doors. Use them on both rear doors whenever a child rides in the rear seat of the vehicle.
If you slide the child safety lock to the lock position before closing that door, the door cannot be opened from the inside. The door can only be opened by pulling the outside handle.

Locking, Unlocking with Door- Lock Knob
Trunk LidMazda 6 Owners Manual: Egr valve removal/installation
1. Disconnect the negative battery cable.
2. Disconnect the EGR valve connector.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Water Hose Removal Note
Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT.)
EGR Valve Removal Note
1. Re ...
Mazda 6 Owners Manual: Service warnings
HANDLING REFRIGERANT
Avoid breathing air conditioning refrigerant or lubricant vapor.
Exposure may irritate eyes, nose and throat. Also, due to environmental
concerns, we urge use of recovery/recycling/recharging equipment when
draining R-134a from the air conditioning system. If accide ...