Q&A

 Master

Allow the interior to dry out, then get a friend to give you a hand, you need to look up from floor level and look under the dash board area toward the lower edge of the windscreen using a flash light to see if the windscreen or any panels or seems are leaking. Does you windscreen have any rust in the area surrounding the windscreen? Many cars have a drain tube to allow water to exit the windscreen wiper area that may be come blocked with twigs and leaves over time. If water can't drain away it will pool up and eventually leak into the interior of the car.
Ensure the liquid leaking into the car is not a leaking heater core in which case you coolant level in the engine will drop, I am assuming the heater core is behind the dash board of the car on this model.

 Enthusiast

1. If air conditioner drain tube is plugged, could run onto carpet. GM has L-shaped fitting to insert into end of drain tube to correct problem with water running back into car. 2. In my case, I removed the carpeting from in front of the seats and sprayed the car with garden hose. Found a leak on drivers side under the dash, above the emergency brake on left side where metal body parts join - not sealed sufficiently causing water to soak carpets on both diver and passenger side, resulting in wiring corrosion. Wiring sets in puddle of water under the carpeting on passenger side resulting in door lock not activating. 3. Leak in windshield at top right corner above glove compartment area can drip onto carpeting. Use windshield sealant and gently lift rubber trim around windshield to let sealant run down between windshield trim and car body to seal any leaks.