Hi all. My 03' A4 Q (114k miles) has started making a new noise. Whenever I am driving over 60 MPH or so and then hit the brakes with any force at all, I hear a popping sound. It sounds like its coming from under the rear passenger side floor board. And its always just one pop and then wont happen again until I drive a few miles. I wasnt able to find anything through searching the forum. Any ideas or suggestions would be really appreciated. Thanks.