I own a 2004 Dodge Caravan SXT with 8700 miles. I have a strange low tone rumbling noise when I accelerate between 20 mph to 30 mph, then disappears. If I accelerate faster between these two speeds, I do not hear the rumbling. The rumbling has no effect on the car's perfromance and drives beautifully otherwise. I have already ruled out tires and bearings, and think it may be coming from the frontend, transmission, engine or exhaust. I am taking the car into a Dodge dealership this week, but was hoping someone out there maybe experienced the same problem and can give me some assistance. Thank you for your help. Marcia