Most likely the drains are clogged. What you need to do is open the sunroof and use a blow gun in side the front and rear tube to dislodge whatever is clogging the tube. After a few good blasts you can try pouring water through the tubes to check to see if that worked.
check sunroof for leakage
Plugged ac drain, plugged sunroof drain, the windows where left down in the rain, torn door weather strip, spilled drink,
Water on the passenger side floor would be a plugged up AC drain. The drain is located under the hood, at the lowest point on the HVAC box on the firewall. However if the floor is wet with engine coolant, the heater core is leaking.
There is a drain on the outside firewall that is clogged.
The evaporator drain allows condensation from the ac unit to drain. When the drain clogs up water will go into the passenger floor instead.
If your vehicle has a sunroof, the drain tube may have popped out of it's outlet. This tube runs down inside the roof support on the passenger side of the windshield, running down just in front of the passenger door behind some plastic. I have a 2003 XRS. It had a really musty smell that we traced to the front passenger side carpet. When I pulled the carpet back, it was dripping wet. The air conditioner drain hose had pulled away from the firewall and was draining into the floor pan. I replaced the tube into the hole and have not had any trouble since.
Are you running the air conditioner? If the drain line is plugged, it will leak water (condensation) onto the passenger side floor.
If it is coolant, a leaky heater core. If it is water, a clogged ac drain or damaged door gasket.
Check your sunroof drain hose. mine came loose and when it rained my floorboard was wet.
The ac drain is plugged. The drain hose is on the firewall on the lower passenger side. ...that, or your heater core is leaking.
Bad heater core? replace Evaporator drain plugged if A/C equipped - try to unplug from under vehicle
If you have a plugged AC condensation drain, clear water will back up and end up on the passenger floor. If the heater core is leaking engine coolant you will have engine coolant end up on the passenger floor.