WAS DRIVING MY MAZDA CX-9 IN AFTERNOON TRAFFIC WHEN THE CAR IN FRONT OF ME APPLIED THEIR BRAKES TO STOP. I WENT TO APPLY MY BRAKES AND THE PEDAL WAS HARD AND NOTHING HAPPENED...THE CAR WOULD NOT STOP. I THEN PLACED MY OTHER FOOT ON THE PEDAL IN ORDER TO APPLY MORE PRESSURE AND STILL NOTHING. HEARD A HISSING NOISE AND THEN REALIZED THIS CAR WAS NOT GOING TO STOP. "SCARED THE HELL" OUT OF ME AS I WATCHED MY CAR HIT THE CAR IN FRONT OF ME. THANK GOD I WAS NOT GOING FAST OR THIS COULD HAVE BEEN TRAGIC. PULLED OVER SLOWLY TO THE SIDE OF THE ROAD AND SHUT THE CAR OFF TO GATHER MY THOUGHTS. APOLOGIZED TO THE LADY I JUST HIT AND COULD NOT EXPLAIN TO HER WHAT HAPPENED, WE WERE BOTH PUZZLED. I THEN SLOWLY MILKED THE CAR HOME TO PARK IT AND CALL THE DEALER. THIS IS WHAT I FOUND OUT....MAZDA KNOW'S THERE ARE ISSUES WITH THE BRAKE POWER ASSIST UNIT AND IT ACTUALLY WAS INVESTIGATED BY THE NHTSA. NOT HAPPY WITH THE FACT THAT MAZDA IS AWARE OF THIS PROBLEM AND NEVER NOTIFIED ME OFF IT. SUBSEQUENT CALLS TO MAZDA AND THEY SAID "ONE" MEMO WAS SENT OUT AND BECAUSE OF THE MILEAGE ON MY CAR IT'S NOT COVERED. REALLY....HOW CAN A COMPANY WILLINGLY KNOW THERE'S A BRAKE PROBLEM AND SEND "ONE" SO CALLED MEMO TO IT'S OWNERS. IF I HAD EVER SEEN THAT MEMO MY CAR WOULD HAVE BEEN AT THE DEALERS IMMEDIATELY. NOT TO PLEASED WITH MAZDA AT THE MOMENT......IF THIS IS WHAT THEY MEAN BY "WE BUILD EXCITEMENT"! I'M NOT INTERESTED!