Most likely comming from your heater exchanger. Tubes from the radiator go thru the fire wall to the inside heater located on the fire wall on the passenger side. Undoing the connection at the fire wall requires a special tool unless you can fashion your own like I did. You have to pull back on a ring and then pull the tubes apart. To reinstall you just push the tubes together and they snap in place. Good luck.
The only hose connections at the firewall that contain coolant are the connections at the heater core. You either have a loose clamp or the compression fitting between the steel and metal parts of the hose itself are leaking. If there is coolant leaking out of an drain at the bottom area of the firewall, there's a good chance that it's leaking from the heater core itself, through a drain pipe which is the same drain pipe that removes water condensation from the air conditioning.
If it's leaking from INSIDE the firewall (away from the engine compartment) you probably have a leaking heater control valve or damaged heater core.
The coolant sounds like it is leaking from the drain hole for the heater core. The drain is usually along the firewall and keeps the coolant from entering the vehicle should the heater core develop a leak.
heater core leaking
Its more than likely your heater core.
You probably have a bad heater core. The heater core is installed in a plastic casing and the spout is there in case it starts leaking. This keeps it from leaking into the floor of the car.
If its inside the cab at the firewall, its probably your heater core which is located on the passenger side under the dash. This repair is usually not much fun. If its leaking in the engine compartment near the firewall, its probably a heater hose that is failing. This is an easy repair
heater core has a leak replace heater core
Bad hose or clamp where the heater core is connected would be the most likely problem.
Leak in heater core.
Any coolant hose could be leaking. Clean the engine bay, removing dirt and grime. Watch closely to see where the leak is. Also check all hose clamps to make sure that they are tight.
The head gasket sits between the head and the engine block if it is leaking out where you can see the coolant, yes you can smell the coolant if it is leaking into the engine no you cannot smell the coolant. You can check the oil to see if it has coolant in the oil if it does then the head gasket might be blown.