The driver's air bag is mounted in the steering wheel.
When air bag crash sensors detect a frontal impact of greater than moderate force, the driver's air bag inflates quickly helping to reduce injury mainly to the driver's head or chest caused by directly hitting the steering wheel. For more details about air bag deployment, refer to "SRS Air Bag Deployment Criteria".
(With Front Passenger Occupant Classification System)
The driver's dual-stage air bag controls air bag inflation in two energy stages. During an impact of moderate severity, the driver's air bag deploys with lesser energy, whereas during more severe impacts, it deploys with more energy.

Front Seat Belt Pretensioners
Front Passenger Air BagMazda 6 Owners Manual: Windshield installation
Caution
To prevent the sealant from cracking or the glass from being
pushed out by air pressure if a door is closed, open all of the windows and
leave them open until the sealant has hardened.
1. Cut away the old sealant using a razor so that 1-2 mm {0.04-0.07 in}
thickness of sealant ...
Mazda 6 Owners Manual: General procedures
PRECAUTION (CLUTCH)
Clutch Pipe Removal/Installation
Note
A common reservoir is used for the clutch and brake system fluid.
1. If clutch pipes have been disconnected any time during the procedure, add
clutch fluid (brake fluid), bleed the air, and inspect for leakage after the
procedure ...