About 3 days ago the ceiling of my TL started rattling whenever I go over a bump. This would be fine except for the fact that I am forced to take an old road to school. The rattle is around the rear passenger side. I've already searched and the only thing that comes up is that it is the sub (which it can't be because it coming from the roof) or the 3rd brake light (I've followed the DIY to get it to stop rattling to no avail). I would love for somebody to tell me a way to get it to stop. And BTW, I just went out of warranty so I would rather not take it to the dealer unless necessary.