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 AdjusterWheel Alignment Pre Inspection
1. Park the vehicle on a level ground, in an unloaded condition*, and with the
wheels straight forward.
*: Unloaded condition.....Fuel tank is full. Engine coolant and engine oil are
at specified level. Spare tire, jack and tools are in designated position.
2. Inspect the tire pressure.
...
Seat belts
Before driving your Subaru Solterra, always confirm that every occupant
is properly secured with a seat belt. Correct usage of seat belts is one of the
most critical safety measures in preventing serious injuries.
WARNING
Carefully follow the precautions below to minimize the risk of injury du ...
Outer Mirror Glass Installation
1. Connect the mirror heater connectors. (Vehicles with heated outer mirrors)
2. Connect the BSM indicator light connector. (Vehicles with BSM system)
3. Press part C on the outer mirror glass and install pin C.
4. Press part A on the outer mirror glass and install pins A.
5. Press part ...