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 AdjusterContact Authorized Mazda Dealer and Have Vehicle Inspected
If any of the following warning lights or the indicator light turns on/flashes, the system may
have a malfunction. Contact an Authorized Mazda Dealer to have your vehicle
inspected.
...
Sunroof Motor Removal/Installation
1. Disconnect the negative battery cable..
2. Remove the rain sensor cover. (Vehicles with auto light/wiper system).
3. Disconnect the rain sensor connector. (Vehicles with auto light/wiper system)
4. Partially peel back the seaming welts.
5. Remove the following parts:
a. Sunroof seaming ...
Entertainment System
Outline
Auxiliary jack/USB port has been adopted.
USB adapter has been adopted.
An audio unit which supports USB devices such as USB memory or iPods has
been adopted.
911 assist function has been added to the Bluetooth unit.
RDS-TMC (Radio Data System-Traffi ...