Over the years I have had this on many of my cars as they get older...indicative of the heater core starting to leak.
If you turn on your defroster does your windshield fog over (rather than clear)? Another symptom.
I do not know what is involved in changing a town car's heater core...most vehicles have it embedded so deeply under the dash that you have to tear almost everything apart to get to it.
If this IS your problem, it's not going to get better...and it's too late for an additive like "Stop-Leak" to do any good. A temporary solution (not so good THIS time of year) is to bypass the heater completely...under the hood you should find two hoses, about 1" in diameter, that attach to fittings by the firewall. One is the heater input, one the output. Disconnect them from the firewall, and attach them to each other using a fitting, or take one off and run the other where you removed the first from.
The good news, no more leaking inside the car. The bad news, no heater function, or worse no defroster function.
Good luck!
Water runs in when it rains. Car is not running. Need help! Water comes in in great quantities.
Passenger's side? Could be a leaking heater core
heater core is leaking.
If that water is engine coolant, the heater core is leaking.
bad door seals
This would be caused by a leaking heater core, or a leak in the plumbing associated with it.
water in passenger floorboard, where is the hose that would cause this?
your ac might be clogged or your draining hose is clogged. its in that area
The condensor drain tube is clogged. Find the drain line and unclogg it.
Have you used your air conditioning lately? The most common reason for water to appear to be leaking on the passenger floorboard is that the condensation drain for the air conditioning is plugged. Unfortunately, the drain is pretty much inaccessible to the average person and I have yet to discover a reasonable method of clearing it other than paying the dealer or a mechanic to do it. The other, less common causes for that type of leak is that the heater core is leaking, in which case the fluid will be antifreeze rather than water, or the door seal on the passenger door may be leaking, or the windshield gasket may be leaking.
because your ovberflow or condenture tube is clogged remove it and just blow it out with air
Would that be when it is raining ? If so you need to caulk around the vent in the fire wall area. If not from rain, then the heater core is leaking, and you will be losing coolant.
A damaged heater core will cause coolant or water to leak onto the passenger floorboard.