Have you taken the back seat out yet, the bottom? Real easy if you haven't. If it's coming from the qtr window, then there WILL be a wet trail anywhere from the bottom of the b-pillar to the back corner of the seat bottom. If it was the door glass, the water would drip down the inside of the door and drain out the bottom, outside the car. Unless your run channel is REALLY cracked int he top corner and the rain was pouring down. I'd check the door seal with a hose first since that is easier than removing the interior plastic to seal the qtr glass. Open the door on the wet side and wipe dry the whole jamb/seal. Cloes the door and run the hose ariound the top and sides of the door seal for a few minutes. You will most likely be able to see where the water may be getting past the seal once you open the door to inspect from the inside.
You dont have a sunroof, do you?...not sure if it was an option in '93