I am losing coolant, it looks like it is in engine compartment close to firewall about the middle of the dash...Am I close? I have had problems before with leaks 2X in the supply lines to the heater core...No moisture inside car, no gunk on windshield, no spraying/steaming in engine compartment, no "chocolate milk" in oil...what is left? Where else could it go. (oh yeah, resevoir seems to be holding fluid, so it is not cracked) Any help would be wonderful, 202,000+ miles!