This worked on the passengers side.

Find and clean your side drain, by pouring a quart of water right down the vent on the drivers side and then look at your feet and see where the water is coming out. That is that hidden little drain and what can happen is it gets blocked up with leaves, dirt, and gunk. On the inside of the car there is a gap in the sheet metal between the firewall and inside the car. When the drain gets a little blocked up or overwhelmed by the amount of water trying to flow out that little hole, it backs up a channel in the firewall, and comes out inside the car.

To clean the drain the trick is to get you a good stiff cable or wire and clean the heck out of that hole on the bottom. Be prepared from a pile of black gunk, leaves, sticks, and anything else that can work its way down that hole. Found a cigarette butt or at least the remains of one cleaning it out. The same water pour check will find the drain on the passengers side. The leak over there comes in around the wiper motor.

Hope this works for you,

Paul

Can not seem to get two pictures in the same post.