You probably have a damaged water seal. Look for cracks in, or missing pieces of that weatherstripping. You can try gluing cracks back together. Replace the entire weather strip if need be. I guess it's possible that water is entering through the back window. I'd inspect that seal real well too. If you've ever had that glass replaced, or if it's cracked, it might be a prime culprit.
Bad trunk lid gasket. The gasket may have come loose or got cut.
Off the water pump
Pay a mechanic to replace it
A 1996 Pontiac Sunfire uses Dexcool coolant. This should only be mixed with distilled water, never tap water. Replace the coolant every 2 years or as needed.
Take it out and put a new one in!
My trunk is leaking. If it's raining, water come in when I open the trunk to load groceries or whatever.
Is located in side right under manifold
heater core is shot...
the water gets into the combustion chamber and comes out through the exhaust pipe as a vapor
Check the rear window washer resivoir.
Maybe. that seat back probably folds into the cabin. If I recall correctly, there is a fabric loop in the cabin that needs to be pulled to release the seat back. I don't know if you can get at that latch from the trunk or not. You might try taking a hair drier to the locks. Just be careful with electricity around water.
Usually right above and in line with the crankshaft pulley