If your vehicle rapidly closes in on the vehicle ahead because the vehicle applies the brakes suddenly while you are traveling in headway control, the warning sound activates and the brake warning is indicated in the display. Always verify the safety of the surrounding area and depress the brake pedal while keeping a safer distance from the vehicle ahead.
Additionally, always keep a safer distance from the vehicles behind you.

Mazda Radar Cruise Control (MRCC) Display Indication
Setting the SystemMazda 6 Owners Manual: Manually Shifting Down
You can shift gears down by operating the selector lever or the steering shift
switches (some models).
M6 → M5 → M4 → M3 → M2→ M1
Using selector lever
To shift down to a lower gear, tap the selector lever forward (-) once.
Using steering shift switch (Some model ...
Mazda 6 Owners Manual: Tire house trim removal/installation
4SD
1. Remove the rear scuff plate.
2. Remove the rear seat side.
3. Remove the fastener.
4. Pull the tire house trim upward, then disengage clips A from the body, and
remove the tire house trim.
5. Install in the reverse order of removal.
5HB
1. Remove the rear scuff plate.
2. Pull the ...