A liquid (almost sure it's water but I could always be wrong) is dripping out near and/or from my exhaust. I've also heard a weird almost draining kind of sound back there every time I turn the car off, so should I be worried, and what do you think is my problem?
Its likely just condensation building up in the exhaust system, which is not unusual. This will normally clear up once the engine has been running for a while and is fully warmed up. If this liquid continues to leak even after the car has warned up or you've been out in it etc, just check that your cooling systems level is not dropping. NOTE:: DON'T ATTEMP TO OPEN THE COOLANT CAP IF THE ENGINE IS HOT! If you're loosing coolant you may have a more serious issue that needs investigating further.
If your Freestar has a separate AC for the rear (a separate fan control), this is most likely the drain for this part of the HVAC system. In this situation, it would be quite normal to see condensate dripping near the exhaust. If it is partially plugged, you might hear water sloshing around which hasn't drained out yet, especially in really humid weather. If you can find the drain tube (which is usually a soft rubber tube), you can run a wire up it and clear any obstruction which might be present.