If there is the possibility of a collision with a vehicle ahead, the beep sounds continuously and a warning is indicated in the multi-information display and the active driving display.

Smart Brake Support (SBS) (Some models)
Stopping The Smart Brake Support (SBS) System OperationMazda 6 Owners Manual: Storage Compartments
WARNING
Keep storage boxes closed when driving: Driving with the storage
boxes open is dangerous. To reduce the possibility of injury in an accident or a
sudden stop, keep the storage boxes closed when driving.
Do not put articles in storage spaces with no lid: Putting articles
in storage sp ...
Mazda 6 Owners Manual: Immobilizer System
The immobilizer system allows the engine to start only with a key the system
recognizes.
If someone attempts to start the engine with an unrecognized key, the engine
will not start, thereby helping to prevent vehicle theft.
If you have a problem with the immobilizer system or the key, consult ...