Another possibility of the brake light on the dash coming on and off is low brake fluid in your brake fluid reservoir. I had the same thing happen on my 97R wagon with the coolant. This little square with a fan in the middle of it kept coming on, then going off, etc., as I rounded corners, went up and down hills, etc. Finally one day I checked the coolant level, and while there was coolant in the reservoir, it was down, just enough to start triggering the warning dash light. If your front rotors are badly worn, it will take more fluid to push the pads against the rotors because of the longer reach. This will drop the level in your reservoir and cause your brake warning light on the dash to flash. Dick