You didn't mention whether it's under the car, in the car? If it's under the car in the front then could be the radiator journal where the thermostat is, the plate where the oil filter is screwed on to, radiator leak, you didn't mention if there is coolant involved. If it's inside the car then door weather stripping, moon roof weather stripping or clogged moon roof drains on that side.
Air leak.
a leak
Either your windshield or driver's side window has a major leak
You need to identify the leak before you can fix it.
Possible cause; If the navigator has a sun/moon roof. I've experienced a problem with the drain tube which will leak down in back of the lining of the head rail and unto the floor, leaving puddles of water on the carpeting.
Sunroof drains are clogged.
A water leak from the radiator in to the passenger compartment is usually a sign of a leak in the heater core. If the water is not from the radiator then there may be a leak in a window or door seal, or a hole in the undercarriage that is allowing water from the road to soak the carpet..
water in passenger floorboard, where is the hose that would cause this?
A leak some where in the system, such as a bad head gasket, a cracked head, a leak from the radiator, a leak from the water pump.
Its crying! Quick get some tissues! And Ice cream!
A leak.
If you can't locate a leak, inspect the EGR cooler.