coolant drip on 1999 Ford Mustang

Hi everyone i have a 1999 mustang i was driving today and felt a huge splash of fluid on my foot i looked down to see antifreeze my level stays at normal but drips large amounts. So i took a look under the hood and at the back of the engine i seen a hole but looked as if there is suppose to be a plug or hose connected that is no longer connected if anyone knows anything about this please reply thank you

Asked by for the 1999 Ford Mustang
sounds like a heater core leaking into the car. take it to a shop and have it checked.