rooling clunking noise under deceleration

What is your question?

recently my wife and I bought an eclipse gsx "awd turbo for those who don't know :)" well anyways under deceleration in any gear I hear a loud clunk that seems to sound like a jack hamer is hitting my undercarriage lol sometimes it sounds like it's coming from the front sometimes it sounds like it's coming from the back, it even does this in a push start situation but doesn't engage motor turn just rolling clunk noise :(. I have a couple of theories but want a second opinion cause both these theories seem quite expensive. can anyone help or has anyone had this issue before?