1. Remove the rear seat cushion.
2. Remove the bolts.

3. Remove the rear buckles.
4. Install in the reverse order of removal.
Front buckle removal/installation
Seat belt inspectionMazda 6 Service Manual: Towing Description
We recommend that towing be done only by an Authorized Mazda Dealer or a commercial
tow-truck service.
Proper lifting and towing are necessary to prevent damage to the vehicle. Government
and local laws must be followed.
A towed vehicle usually should have its drive wheels (front wheels) off t ...
Mazda 6 Service Manual: Cruise Control (Some models)
With cruise control, you can set and automatically maintain any speed of more
than about 25 km/h (16 mph).
WARNING
Do not use the cruise control under the following conditions: Using
the cruise control under the following conditions is dangerous and could result
in loss of vehicle control.
...