This one is driving me nuts.Its been raining a ton lately and I am getting a big water leak in the passenger side floor .Looks like its coming from the top of the firewall above the blower motor comes right down the firewall to the feet.I took off the black piece under the windshield wiper arms and for the life of me I can not figure out where its coming from.Anyone else had this problem and know where there is a gromment or something that could be causing this.

 

Does this occur when the car is at rest or only when moving?

You could check under the A-pillar covers and see if the drain for the sunroof is the source.

 

When it is sitting say it rains over the weekend(alot) go out to move the car and looks like someone dumped half a gallon of water in it above the firewall,but I have to move it before it falls to the floor Windshield seal is good.

 

Still a good thing to check...completely independent of the windshield seal.

 

remove the doorpanel, remove the pillar trim and wait for the next heavy rain.

I had 2 cars with leaks and try as I would with a hose could not simulate mother nature. First heavy rain I found that leak in about 10 seconds.

Meanwhile check the drains at the bottom of the doors.

 

you also may want to remove the wiper panel and check the body sealer underneath. i've had FB's with cracked sealer and because of this, was getting puddles of water on the driver's side floor. the dash had to be removed in order to completely seal the leak.