So I am at a family party and some of my cousin's want to hear my system....so I turn it on and we are all standing outside listening to it, when I I hear this really bad rattle, coming from underneith the car. It is so bad I can't hear the bass, so I tried to see what it was, but I couldn't feel anything rattleing (This was me just trying to get under it and see if I could see anything no jacks or anything) I think it might be my exhaust?? I don't know what it is. It was really loud...what I was thinking on my way home is that since it has been cold here that some of the metal parts have shurnk, so it is rattling? Anyone have any idea what it could be? I am lost....

 

Maybe an exhaust heat shield or something.