Front windshield is leaking above passenger side

Check the cabin air intake. Chances are the weather strip that lines part of the opening has come off. The intake should be accessible beneath the trim at the base of the windshield on the passenger side.

Are you certain it is rain water? It could be condensation from the A/C coil that fails to drain out of the drain pan, or possibly coolant from a leaking heater core. If you are certain it is rain water, depending upon the age of the vehicle, and possibly some other things, here are the possible options:

1. Leaking door gasket.
2. Leaking windshield seal due to rust
3. Leaking windshield seal due to improper installation
4. Leaking windshield seal due to acoustic (sound) over pressure (if you have extreme sound system with heavy bass)
5. If you have a sunroof, if the drain hose comes down the passenger side door column, it could be leaking into the passenger compartment rather than drain through the floor pan.

sell the vehicle unless you are willing to spend about 3000 to replace the adjusters that move the top up and down

Is it antifreeze? If so, you have a hole in your heater core?

I would say you have either a bad seal on the windshield or the seal on the passenger door opening.

You could have a leaking windshield seal, and its running down the inside of the dash and onto the mat. Has the windshield been replaced?

my dodge caravan started getting a soggy passenger floor during heavy rains. it was solved by replacing the rubber seal along the windshield, on the outside of the van.

sounds like you have a window seal leak.  The only other way water will leak into the car is a leaky heater core or a clogged A/C drain.  Do you have a sun roof that could be leaking?  As they have drains too. 

With the carpet removed,hose down the windshield,side doors and rear doors.have someone inside to watch for water.If the windshield is leaking it may take some time to get to the rear.My van did the same and it was the front windshield.

could be that when it rains or is wet out that water is leaking into your car under the hood under the vent by the windshield wipers on the passenger side and instead of being filtered out its going into the car on the passenger side floor. (check to see if this is wet after a heavy rainfall) and causing a short and rusting it out. this happened with my 2002 grand prix just this year. I got a water resistor for like $3.50 from a local pontiac dealership/parts store and put it in. Its easy to install and it poured out today and my car didnt leak at all.