coolant issues and leak need help.

[Desperado]

first off i have a 89 mustang gt with auto tranny. i can see coolant after driving dripping from the transmission right below the torque converter. this leak is like a drop every 5 seconds and will continue till the car is turned off. once off it will stop dripping after a min or two. where could the be comming from? i can't seem to find the source. also when the car is warm and i turn on the heater and have it on vent it puffs steam when i turn it on and then goes away. WTF is going on. i have been fixing 2 leaks and now i got this last one and the steam issue. please help. i already replaced the thermostat and gasket and it is dry and i replaced my 2 heater hoses at the firewall. just have these last 2 issues. please help. the drain for the heater core looks like it is a tad wet but no water trail from it.