Good evening all...I have been struggling for a while now driving my 2012 VW Passat 3.6L. There is some sort of awful vibration or rattle coming from what I think is behind the passenger back seat. At first it almost seem like some sort of blown speaker because that is kind of what it sounds like. But then my theory was shot when I was driving with out the radio on and it still happened. I?ve been paying attention to if different road surfaces affect this I.e fresh pavement, older pavement, highway, county roads etc. the sound happens just whenever so the road conditions didn?t really factor in but I do think it happens more on rougher older pavement....has anyone else had a similar experience and been able to resolve?