Hmm,
My first attempt of posting pics failed.
Lets try again:

Did you make sure the drain hoses aren't plugged?

Okay,
This time I will use links to the pics. Should work.

Will, it'* funny you mention the drains for the sunroof.
And yes, along with pre-shrunk weather stripping, GM should have considered clamping the drain houses to the drain spouts!

Today was fairly successful. I discovered the drain tubes were disconnected from the rear sunroof drain spouts, resulting in water coming down the headliner, past the rear trim by the rear speakers, down the back seat, and into the rear floor pan:


The result is a soaked underpad and soaked rear passenger carpet:


A few short cuts were made today: You can release just the rear of the headliner by removing the rear interior light and holy sh*t handle assembly, removing the back trim by the speakers, the weather stripping from the top of the door, then gently pulling on the headliner to release it from the velcro. This allowed me to re-attach the hoses, and tighten them to the tubes using a gear clamp:


I was also fortunate enough to not have to remove the front seats. I moved the front seats all the way forward, pulled up the carpet to see how far the leak went, and was happy to find it was only in the back of the car:

Notice the start of rust on the floor?
I removed all of the soaked under pad and threw it away. The carpet is only wet up to the front seats:

By raising the front of the car, I was able to check the re-attached drain tubes, and am happy to report the water now drains to the outside of the car, not the inside! This also helped in having the water move all the way to the back of the floor pans so I could soak it up with a towel.

After a quck trip to the car wash, and using the Super Vaccuum, the carpet is now nice and dry.

After removing the back seat, I found the padding under the seat to be ruined as well.
Here we see a turtle coming out of the pond, searching for dry land:

The bottom of the seat is completely soaked. It is now drying on my back patio, the bottom padding is like a sponge.

Onto the weather stripping.
Probably also a source for rain water and wind noise, mine have shrunk pretty bad. After some gentle pulling, this is how the rear door frame looked:


I removed the bottom trim from the threshold and was able to start pulling it up. It was still firmly attached to the top of the door, so I grabbed some black silicone adhesive and applied it to the curves of the door frame and pressed it in. The result is a nice, tight seal. Here it is all fixed up:


You wind up with a gap at the bottom of the door, which indicates just how much mine have shrunk:


This gap will be filled by a splice from the stripping picked up from the local junk yard, and I'll silicone the seams.

Here is another spot that was pretty loose:


I siliconed the heck out of it, and re-applied.

It'* raining out right now. It should be a good test to see if my work today paid off!
Tomorrow shall bring a trip to the carpet store for underpad, and install the splices into the gaps of stripping. Some final re-assembly, and we'll hopefully be off and running.

I will be sure to post some updated photos as the final assembly comes together.

Cheers,
Adam

Wow...you weren't kidding about turtles. Good work. Honestly.. Pulling the front seats is easy.

Hi,
And thanks for fixing up my picture links. Makes it a bit easier to review.

Yes, I was going to pull the front seats and check those areas properly, but due to time constraints and encroaching nightfall, I just pulled the carpet up behind the front seats and ran my hand under. I was happy to find that area to be dry.

More happy news: After last nights rain, the car is bone dry inside. Take that, turtles: go live somewhere else!
I managed to fix my sunroof up too, just needed more height adjustments.
Wow, when all of this is over I can concentrate on my important things, like performance mods!

Within a day or two I'll have some new pics as the final assembly is completed.

Adam

Water problems suck. Glad you fixed them. A dry car is a happy car.

After discovering my front windshield leaked and ruined my headliner, I decided to remove it and recover it. Only one problem, it has been wet so many times that it just crumbled in my hands. So i decided to look around the car and see if i needed anything else b4 going to the junkyard. When i looked in the trunk I noticed the carpet was wet. pulled it up and there was a puddle on the passenger side about 2 inches deep. And where my spare tire should be it was completly full of water. I mean if i had spit in it, it would have been all the way to the top of the spare tire well. I looked on the leak thread on here and checked all the places, back window seal is good but i caulked it anyways, and the taillight fittings are all there and tight. Any other ideas where this water could be coming from. Im at the point now of squeezing my 300 pound body in the trunk with a flashlight and having someone close the lid and turn on a hose.

Tony... enjoy being in the trunk.. that'* the most effective way to find your leak.

That'* exactly what mine looked like when I got it. Luckily, one of the first things I did when I bought my Bonne was to run her through a car wash.

It sounds like you did a really good job of tracking everything down and gettin' her fixed up!!