Mike, the remove the panel you asked about, remove the windshield wiper arms (not just the blaeds, remove the arms from the posts, then you will see about 6 or 8 screws holding that panel (the "cowel") in place. It is plastic and with the screws removed it will lift up. A few people have found an open seam in the space under it.
The brake pedal is a possibility.
The condensate (water) drain line from the air conditioner sometimes becomes plugged and causes condensation to accumulate and drip into the passenger compartment, but usually this water drips onto the passenger's feet.
Last idea I have is that sometimes the windshield itself leaks and needs to be reset, or have special adhesive applied around it. This is easier with the old style windshileds, because you can remove the metal trim so seal the edge of the glass. You have the new style and the rubber gasket is attached to the glass before the glass is installed in the vehicle. If it appears this might be the problem, you would have to ask a dealer or an auto glass shop how to seal it.