I currently have taken my car in 8 times for a thumping noise in the rear of the vehicle. It happens at a stop light with car in drive that it makes this noise (sounds like in trunk) and is so loud and can move the vehicle that sometimes feels like someone hit you from behind as the entire car moves. They changed the sway bar, said it was the differiential and took out the actuator power doors and now they are changing out something with the emissions but it still makes this noise. Makes it with both a cold engine as well as running for a while. Has anyone had this problem? HELP.