Hi -
should have taken a picture of course, but a couple of times recently I've noticed a small wet patch on my passengers side carpet (UK, so left hand side if you're in the car facing forward).

I have a feeling this is leaking down underneath the carpet and making the sound proofing damp as the carpet has felt damp in the past, and the underside is pretty well sealed now (i.e. I don't think it's water coming up off the road)

The visible damp patch is on the highest point of the carpet, at the front of the door opening, right where the plastic trim meets the carpet.

When I opened the door I could see a tiny streak of water on the plastic up by the fuse cover, and it looks like there's a seal on the car body that channels water down into a drain, and that the water has leaked from the top of the part that channels the water away.

When I've cleaned the car previously I targeted the passenger door with a hose but didn't get any sign of a leak. It seems to happen after very prolonged rain. I checked the drains by the windscreen and they weren't blocked.

any ideas on a cause/fix? Nothing looks torn or damaged in that area. I could whack some silicone on it but that isn't the most elegant of solutions.