2017 Toyota Aygo
The carpet underneath the mats on the driver's side of the car became wet a couple of months ago.
I asked for the dealership to diagnose the problem, and they ruled out the windscreen and the doors.
They tell me the cause is the tailgate third brake light and it has to be replaced.
I have a hard time believing water is getting through the brake light and going to the carpets with no damage to the headliner and the boot being dry:
This is after they removed the stop light and the seal on the back of the spoiler.
To me, the water would either flow outside of the car because of the boot lid rubber seals on the picture, or go to the headliner through the rubber sleeves next to the yellow circle.
I have also found two photos of the Aygo tailgate spoiler showing it doesn't share any connection to the main body of the car:
Am I wrong saying it doesn't seem to be the cause?