If our RX8 coils suddenly stall when we are running normal around 60km/h and then the engine wont start again (no fire) then what would be the cause? Can it be cause by a broken electric fuse (maybe)..? Or any other cause? Kindly advice me, thank you..

 

Make sure your battery connections are secure.
Are you getting any "Check Engine Lights"?

 

Battery connection secure, all lights, audio and indicator works fine.. CEL flashing rapidly.. No symptoms of losing power, only suddenly dead..

 

Flashing CEL is a sign of your engine misfiring. Though, I don't know if that would shut down your car...
When was the last time you had the spark plugs and ignition coils changed? Any other maintenance done on your car?