Been there done that. Fixed the #$^%($$ gaping hole under the hood hinge which allowed a deluge of water to come in. I pulled all carpet and driver's side seat out and directed water to the corner of the hood to be sure, then the fresh air intake, then the window gasket....no leaks detected.

Then I moved to the side of the car and directed water to the door edges, along the base of the window, and then the space between drivers' front and rear doors. After waiting for a few minutes I did then notice that there was a tiny trickle coming out near the "hump" that supports the front 2 bolts of the seat...there was water seemingly oozing from the inner sill just behind the "tunnel" where the vacuum lines, etc. exit.

Upon closer inspection and some careful screwdriver work, I found the metal was rusted through the sill and also through the floor. To give you an idea of location: go underneath the running board and locate a rubber drain which is sort of streamlined, pointing towards the rear of the car. Pull it. This is apparently where water was collecting, not draining, and then slowly rusting out the sill and floor.

So: NOT sunroof, NOT front window, NOT window seal, NOT A/C evaporator hose, NOT hood/hinge drain. A NEW AND EXCITING PLACE TO FIND RUST!!!! I almost peed on myself I was so happy (LOL) to find my car insists on being different.

I've repaired with mesh and fiberglas (it was a relatively small area) and because it's like the freakin' Pacific Northwest here I'm sure it'll pour down rain in the next couple of hours so I can check the viability of my repair.

Ok, love my car, love everything about it, thinking about being my car for Halloween but I'm getting majorly sick of having to repair rust. My car doesn't have to be a perfect beauty but I'd rather do things to improve the performance than just tread water, literally. I suppose I should have purchased from California or something.