Thanks. I looked under the carpet but didn't see any signs of leakage. I don't smell coolant inside the car, although I get a little fogging when the heater is on, but nothing serious. I looked between the inner and outer firewalls and didn't see any signs of leakage where the hoses connect to the core. My thought is that the core might be leaking inside the heater housing, and the coolant is then draining out the condensate drain for the AC heat-exchanger.