Rear quarter window?
Update: Took it in Monday to have their "leak" guy check it out. Well he said he got it to leak just a little and fixed it. We had a big rain storm last night so I go out there this morning and it looks the same with a big ass puddle in the back floorboard on drivers side.
I did park it facing downhill a couple days before I took it in and nothing was wet after raining the night before. So it only leaks when it's parked facing uphill. I told them that also and they only had it on level ground when they tried to make it leak. When I washed it the other day I couldn't get it to leak with a water hose but I was on level ground. Any ideas on what it could be?
Certainly with this scenario it is pretty clear it is coming from ahead of the rear floor plan now.
Feel around up around the top left corner area almost in back of the hood latch area on the driver side. Many cars tend to leak up and around the bulkhead seam. I have seen it many times. Feel around the dead pedal area and see if it is damp up there.
Hardtop or vert? A guy on Stangnet was having an identical problem on a new vert. Don't recall ever seeing the outcome.
Hardtop. Can you try to find out who it was and if it got fixed.
Posted question last night; no answer yet. Here's the link.
I think you're onto something though. I haven't pulled a sill plate on these cars, but on most cars there's a channel underneath that wiring runs through. As stated above, it's possible that a missing plug, or seam sealer gap could allow water to flow down, get into that channel, and run to the back, bypassing your front floorboard.
You said you pulled the sill plate--did that get you to bare metal, or was there additional plastic cladding before you get down to the body in that area?
I took my backseat out and pulled the carpet back a little. Took my sill off from the door that says "svt". Put a water hose on the wiper cowl area on drivers side, that's where I've been reading about everybody else's problem. But my front floorboard isn't wet. Well after a minute or two with the hose, I look and see water settling behind drivers seat in floorboard. I didn't take the seat out cause I don't have any tools here. Nothing else is wet from the front to the back. Is there a secret passage from the front wiper area to back floorboard?
Just metal. The wiring runs along the trim by the door no channel there. I'm gonna get my buddy to help me this weekend. I'm gonna pull the seat out and pull the carpet back a lil more. It's a gag that an almost 70k vehicle that has 1k miles on it does this.
check and make sure the kick plate is snapping all the way in, It sounds like you're maybe missing the last snap on it or something similar. check to see if it seals flush against the car, and the weatherstrip on the door as well as the weatherstrip on the body of the car is solid.