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: Advanced Keyless Entry System
WARNING
Radio waves from the key may affect medical devices such as pacemakers:
Before using the key near people who use medical devices, ask the medical device
manufacturer or your physician if radio waves from the key will affect the device.
The advanced keyless function allows you to lock/u ...
Mazda 6 Owners Manual: Front brake (disc) inspection
Brake Judder Repair Hint
Description
Brake judder concern has the following 3 characteristics:
Steering wheel vibration
Steering wheel vibrates in the direction of its rotation. This characteristic
is most noticeable when applying brakes at a vehicle speed of 100-140 km/h
{62.1-86.8 mph}.
F ...