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: Seat Belt Extender
If your seat belt is not long enough, even when fully extended, a seat belt extender
may be available to you at no charge from your Authorized Mazda Dealer.
This extender will be only for you and for the particular vehicle and seat. Even
if it plugs into other seat belts, it may not hold in the ...
Mazda 6 Owners Manual: Steering gear and linkage inspection
Rack Inspection
1. Inspect the rack for cracking, damage, and tooth wear. Replace it as
necessary.
2. Measure the runout of the rack.
Runout
Near point A: 0.15 mm {0.006 in} max.
Near point B: 0.20 mm {0.008 in} max.
3. If not within the specification, replace the rack.
Tie-rod End ...