We purchased a Certified 2007 MMH with 19,000 miles. Occasionally and unpredictably there is a very loud noise that lasts a second or two that seems to becoming from the rear of the vehicle. It sounds somewhat like you would expect if a tire was rubbing against the wheel well. It seems to happen more frequently if the vehicle has sat idle for several days. The noise is very loud and sounds like something that could be causing damage. Has anyone else experienced anything along this line? I'm reluctant to take it in to the dealer because it is unlikely we could duplicate the situation.