I have an 06 8, lately I have been noticing a lot of cracking and rattling come from the speakers in the rear, and also the small tweeters on the driver/passenger door, the sound quality is slowly deteriorating. I have checked the tightness of all the door panels, and nothing seems to be loose, however I am getting this crackling noise from all over the place and it is bothering the sh$t outta me. I generally turn the music up when driving so I don't have to hear this. Anyone have any advice on steps to mitigate this? Is there something I am missing?

 

search for a thread titled 'Rattle Hunt" or something similar to that

 

Have you checked if your Bose Amps in the door panels are working? You can turn on the radio and tap the area near the door speakers to check. If the sound is intermittent, then there's either a loose connection or a bad relay inside the Amp. Search for Bose amp and scan for the door related threads - hope this helps.