Muffler loose and rattling. But also when car is not running i get into car and get right into drivers seat shakeing the car you can hear it. (im not fat) But im really worried! And when the car is in reverse or strong winds or speeding up those are factor's that make it sound horribe. Also i moved the tailpipe and somewhere in the middle of car not back rattled. So basically somewhere in the middle section car. What would this be?