2006 Lexus IS Brakes Problems

THERE IS A LOUD NOISE COMING FROM UNDER THE HOOD WHEN YOU PRESS ON THE BRAKES. WHEN STEPPING ON THE BRAKE BEFORE COMING TO A FULL STOP THERE IS A PUMPING NOISE. FROM THE FRONT ENGINE AREA. THE BRAKES LOCKED UP ON ME WHEN I WAS PARKED AND TRYING TO START THE CAR AND I WAS UNABLE TO START THE CAR. I PUMPED THE BRAKES AND TURNED THE WHEEL AND IT STARTED. WHEN SITTING STILL AT A LIGHT WITH MY FOOT ON THE BRAKE THE NOISE FROM THE FRONT ENGINE AREA GETS LOUDER. THE SOUND IS A LOUD, KNOCKING, IDELING SOUND. IT FEELS LIKE SOMETHING IS STUCK, LIKE THE CAR IS TRYING TO RUN PROPERLY BUT CANT BECAUSE SOMETHING IS STOPPING IT. THIS FEELS LIKE AN ABS SYSTEM ISSUE. I HAVE HEARD THAT OTHER LEXUS OWNERS ARE HAVING THE SAME ISSUE WITH THIS SAME MAKE AND MODEL. THIS IS A DANGEROUS ISSUE THAT NEEDS TO BE LOOKED INTO. THIS IS AN ACROSS THE BOARD ISSUE AND IS AFFECTING WAY MORE THAN JUST A FEW CUSTERMERS.

REAR BRAKE CALIPERS SEIZED, NEEDED REPLACEMENT. EXCESS RUST, MATERIAL APPEARS DEFECTIVE. ALSO CAUSE OF REAR BRAKE PAD REPLACEMENT. *TR

MY WIFE'S IS 250 WAS TAKEN IN FOR IT'S 40,000 MI. OIL CHANGE. SHE RECEIVED A CALL THAT THE REAR BRAKES NEEDED NEW ROTORS, PADS AND CALIPERS. I CALLED AN WAS TOLD THAT THE REAR BRAKES WERE NOT WORKING AT ALL BECAUSE THE CALIPERS WERE FROZEN. I WAS ALSO TOLD STRANGELY ENOUGH THAT THE ROTORS WERE RUSTED AND HAD A RIDGE ON THEM AND COULD NOT BE MACHINED DESPITE THE CALIPERS BEING FROZEN. ONE PROBABLE CAUSE I WAS TOLD WAS BECAUSE THE CAR HAD LOW MILES ON IT. IT GETS DRIVEN EVERY DAY ABOUT 20-30 MILES. ACCORDING TO THEM MY WIFE WAS DRIVING AROUND IN A CAR WITH NO REAR BRAKES. I HAVE YET TO RECEIVE A SATISFACTORY ANSWER FROM THE DEALER ABOUT WHY THIS COULD HAPPEN>