I had exactly the same problem on my previous Jeep Cherokee, only after a couple of months I figured out from where it was coming from, for various reason it was not happening all the time, (intensity of the rain, wind direction, if the truck was parked on a non-leveled ground, …):

Behind the inside door panel there is a plastic sheet, glued to the door metal frame usually with "pitch", there was a place where that plastic sheet was not glued anymore at the bottom. Water dripping on the window, then inside the door was running along the plastic sheet finding it’s way through the “hole”, running along the inside door panel and dripping on the rubber over the rocker panel and finally on the carpet. When I removed the inside door panel I actually found that it was the case, fixed the plastic sheet and it never happened again.

This is what is probably happening to you, good luck.

 

Well, I looked at the way the GV's door is built, may be I'm wrong, but I don't think what I wrote in my previous message is the cause.

 

Well, it definately leaked yesterday. On the way home, I had made sure before I left work it was fairly dry. after 35 minutes of driving in wet conditions, there was about 3 or 4 tablespoons of water in the indent. And wet all along the carpet side of the door. Question, how do you take off the rocker panel cover, the plastic one that seems to be connected near the front of the door to the rear of the door. It must just be clipped in as there are no screws but I'm hesitant to force it especially in Winter, Thanks, Dave

 

Had this once with a Vitara... turned out to be a faulty windscreen (bonding was shot).. could also be the door rubbers not fitting well