Depress the button on the seat belt buckle. If the belt does not fully retract, pull it out and check for kinks or twists. Then make sure it remains untwisted as it retracts.

NOTE
If a belt does not fully retract, inspect it for kinks and twists. If it is still not retracting properly, have it inspected at an Authorized Mazda Dealer.
Fastening the Seat Belt
Front Shoulder Belt AdjusterMazda 6 Owners Manual: Lane-Change Signals and Three-Flash Turn Signal
Lane-Change Signals
Move the lever halfway toward the direction of the lane change—until the indicator
flashes— and hold it there. It will return to the off position when released.
Three-Flash Turn Signal
After releasing the turn signal lever, the turn signal indicator flashes three
times ...
Mazda 6 Owners Manual: Smart Brake Support (SBS) (Some models)
The Smart Brake Support (SBS) system alerts the driver of a possible collision
using a display and warning sound if the radar sensor (front) and the Forward Sensing
Camera (FSC) determine that there is the possibility of a collision with a vehicle
ahead while the vehicle is being driven at abo ...