Hoping someone can give me some guidance... (Gilly - would really appreciate your input from your experiences.)

2000 ML320

Let me paint the picture...
My W163 has a moistness on the floor in the front drivers and passenger (less there) after a recent rain. Only moist at the carpet closest L & R front corners to the front doors. No musty smell - is new water. Truck is parked outside pointing slightly downhill. Seats (leather) are dry. Temps in 40's (not using A/C in at least a month). Today checked both front L & R sunroof drains and water goes through with no resistance. Where can the water be coming in?

I suspect the upper seal on both sides running from the front fenders going up along a-pillar across top of body over the B pillar ending at the rear of the back door opening might be tired and needs replacing. I do see at the rear of both these seals water tracks from the rear of both leading onto the rear door seals. I consider this upper seal the first defense against water entering the vehicle. Second are the door seals themselves (on the doors).

Anyone have such an experience? I'd really appreciate the feedback and possible solution.

Anyone ever replace these upper seals? Hard to do? Anything needed other than the seals themselves for the job?

A general thanks in advance for feedback.

Autobahner