hi im not sure if this is the correct place to post this. i have a countious knocking/rattling noise, like something loose, comming from the rear passenger side area or under passenger side rear under door area. took it to mechanic and they cant seem to locate the noise. the noise is always there and the only way it goes if i go over dirt road with lots of potholes. it goes but when i shut the engine off and start it again its back. any help to find the source would be greatly appricated. driving me nuts