Just because the carpet is dry doesn't mean the heater core isn't leaking. Just ask...me! I had coolant dripping from the same area you are. There is a drain hole in the heater box that will let coolant outside the car instead of inside the car. I thought it was a damn freeze plug at first-nope-heater core.
The last time my GT was dripping coolant from the bellhousing it was a cracked block
I'd guess you have a leaking heater hose, bad heater core, coolant leaking from the back of the intake, or a freeze plug that has gone bad. There are no freeze plugs on the back side of the block in the bellhousing.
My car did the same thing. I did a pressure test and came up with nothing. I just left it alone and let the overflow tank run out. After it was empty the leak stopped. I don't know if it was overflowing and tracing the frame rail back or what, but it is not leaking any more.