My car had the same problem couldent tell u exactly what it was but i pulled the glove compartment out,pulled the carpet back,took out the ecu(cause it was in my way).so i had my dad hold the hose directly over the cowl pannel, took a flash light looked up and saw it driping out of some yellow factory cocking. so i took a hand full of clear bath room cocking and smeered it all over the leak never happened again to this day.

just remembered the heater box also might be in the way.