Ford F-150 - 1997-2003 :: 1999 - Antifreeze Leaking On Passenger Side Coming Down The Firewall Outside?

99 f150 4.6 4x4 ... auto.. so, driving on the interstate I had to accelerate hard to avoid hitting a crazy driver... after that I smell antifreeze... get home can't find a leak.. wait a bit and I see antifreeze leaking passengers side coming down the firewall outside... if you are laying behind the passengers front tire with your feet to the back tire.. looking up you see the catalytic converter.. behind that on the firewall a stream of antifreeze... follow the stream up and there is a piece of plastic just about were the firewall starts to go straight up from the floorboard bend.. putting my hands in that it goes inside..and its wet inside..

I can't tell what that's for really but. Am I guessing evap coils access? any rate. I don't feel any dampness inside yet.. but I do smell it in the cab stronger now. I haven't ripped up the carpet either. Im suspecting my heater core sprung a leak?? there is a good amount of fluid coming out and down the firewall outside I would say I have about a 6-foot puddle now. course I parked on a hill too. no fluid that I can tell is at all leaking off the heater core hoses.. they felt dry. Im guessing there is a drain port in that black box inside and that is where this is coming out?? no noticeable leak from the motor side.. it's all dry.. its actually going down the firewall and hitting a metal plate that carries out to a cross member on the transmission and then leaking down.. motor area is dry.