The front passenger side of the floor is always 2005 DOdge Carava

Is it wet with water or coolant? If it is coolant you have a damaged heater core. If it is water it could be from a windshield with a bad seal, a leak in the floor or possibly an air conditioning system with a plugged drain tube. There is nothing else that would bring water in from the vehicle. If your are a cold climate and snow gets in on someone's boots it will melt and wait till dry weather to clear.

Have you checked your antifreeze levels lately this kind of explanation leans towards a blown heater-core ..do you find yourself adding more to the radiator if you have noticed this is why .

otherwise if not i would ask if you have either been in an accident or in a body shop for repairs ..if so something has been overlooked in repairs/

but i am going to say most likely the heater-core check your 'radiator fluid levels for loss of fluid