It could be one of two things. Unless you park under a tree where a lot of debris can get into the grate under the windshield it is more than likely the A/C water drain. It is probably kinked or clogged. You should be able to see it exiting the firewall on the passenger side very low on the wall. Just examine the tube and don't jam anything to hard into it as it may become dis-connected. You may have to remove the air box inside the car under the dash to get to it and see if it is cloged.
Yes, there is a drain box under the front windshield that has weep holes at either end near that exit inside the fender well. You might have a gasket leak somewhere in the cowl system. Depending on whether your fresha air box intake is plastic layers or a metal grate determines how you will go about fixing it. If you have pastic panels just order all the retainers and seals and remove everything, clean it out and replace everything. If it is metal you will have to work under dash and possibly have to remove at least the lower feder bolts so you can clean out the weep holes.
In either case you want to do something soon as your car's computer is genrally in the passenger footwell and it will get correded and cause problems. They can be purchased rebuilt but they are not cheap, so don't hesitate to get at fixing this situation. Keep it as dry as possible.
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Friday, December 28th, 2012 AT 3:41 PM