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: Tire Inflation Pressure
WARNING
Always inflate the tires to the correct pressure: Overinflation or
underinflation of tires is dangerous. Adverse handling or unexpected tire failure
could result in a serious accident.
Use only a Mazda-genuine tire valve cap: Use of a non-genuine part
is dangerous as the correct tire ...
Mazda 6 Owners Manual: Recommendations for Shifting
Upshifting
For normal acceleration and cruising, Mazda recommends these shift points:
*1 Always observe local speed limit regulations.
Downshifting
When you must slow down in heavy traffic or on a steep upgrade, downshift before
the engine starts to overwork. This gives better acceleration w ...