99 STS Leaking water from Drv/Sd Pillar, Help!!!!

Ive noticed that whenever it rains the top left side of the driver side pillar (between the windshield and door) it starts to leak. Its starts off slow then continues to pour until it's soaked. I looked at the weatherstripping on the windshield and couldnt find anything there as well as the moon roof. Its really anoying so does anyone know how to fix this?? Any suggestion would help:banghead:

the best way to trace a leak is to sit inside the vehicle and have someone spray the area with a hose and try to narrow down the area leaking. some leaks are a real pain to locate. but spraying a small area at a time and waiting for the water to drip will at least help you narrow it down. make sure to cheack any seam areas in the weatherstripping or for any dryed out parts of weatherstripping. ive seen leaks come in from the oposite side of the car and trail all the way to the other side before leaking into the car. i would suspect the moon roof before the side pillar. good luck...hope this helps a little if any.