I think I need to start this off with a declarative statement: I fear the headliner!!
1985 300TD. The wagon.
Every time it rains water runs down my driver's side A-pillar, then runs to the rear floorboard. I always sop it up, but it gets under the floor insulation, and it is gonna rust my floor pan at some point.
No wonder the sunroof was caulked shut when I bought the car.
First, the drains have all been verified clear. Found a great tool at Harbor Freight for this. I have removed the front valance, mirror, sunvisors and A-pillar trim. The front drain connection is not leaking at all. But the water comes down the A-pillar, drips through onto hood latch pull and emergency brake pedal. It isn't the front windshield or any of the drains. I have seen the water flowing down the headliner to the front left A-pillar, so it is coming from the sunroof somewhere. Even small rains cause water intrusion.
So, it would seem that I need to lay eyes on that rear drain/tube connection point. Doesn't that sound reasonable at least?
Which brings me to the point of having to try and mess with the headliner without ruining it. I would love advise on that subject.
I can take the sunroof cover off, then remove the slidable sunroof portion, but can't see way back into that corner.
I'm all ears and eyes..........

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John