OK, so I'm driving to West Virginia yesterday evening and once I arrived at my destination I saw steam seeping from underneath my hood. When I checked under my hood I saw that my antifreeze/coolant was steaming, actually boiling and leaking out the bottom of my car, once I returned to my car, all the coolant had leaked out so I drove to the gas station bought more coolant and drove my car home. The next morning I took my car to my mechanic and he said he couldn't find anything wrong. Can someone give me some insight into this matter? Thanks a bunch!