I ran across an old thread here that had the same issue. In his video, he had fairly loud music playing with heavy bass. But in another video he posted, with no music, he didnt have the problem. I seem to recall looking at footage from my cam mounted in my personal car while I had loud music playing and the sub was causing a similar disturbance in the picture. I think it has something to do with the camera not having a shutter and the vibrations caused by low freqs passing through the windshield into the suction cup and then ultimately to the camera body. It must be susceptible to a certain range of lower frequencies.