Keep watching the passanger front floorboard & top edge of the carpet. Also look for a "fog" on the bottom of your windshield. These are all signs that the heater core (inside dash) is failing & needs replacing. I guess you should check the rear carpet too, as there is also a heatercore back there. I would also watch the coolant level in your overflow container (underhood).
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The 1960 Thunderbird. Unique in ALL the world. | 
