I have a 03 B6 3.0 A4 and just this morning i had an issue with the brake pedal, when you put your foot on the brake pedal firmly the pedal stays down about 1 1/2 inches and brakes remain on, even trying to get your foot under the pedal and lifting it doesnt help. drag heavily then finally the pedal will pop back up and relaese with a thud. Any ideas would be much appreciated.