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: Dtc c1095, c1096
Caution
When attaching the tester lead to the ABS (ABS/TCS) HU/CM harnesses
connector the SST (49 G066 001) must be used. (See ABS (ABS/TCS) HU/CM
INSPECTION.)
Diagnostic procedure
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Mazda 6 Owners Manual: Rear window glass installation
Caution
To prevent the sealant from cracking or the glass from being
pushed out by air pressure if a door is closed, open all of the windows and
leave them open until the sealant has hardened.
1. Cut away the old sealant using a razor so that 1-2 mm {0.04-0.07 in}
thickness of sealant ...