not always but when I open the tailgate there is water on my Ford Boot Liner (good job have that !), on left side between corner and latch, close to the bumper, can't see any water anywhere else or any damp anywhere. All my seals still look like new, no damage not dirty not twisted all looks as always has done. Thinking it's for some reason running down the channel of the seal around the bodywork but then falling inwards, I put some grease in the channel other day and actually was worse quite a lot of water got in from the heavy rain. Can't fathom it out ?

The only way you'll find it is by sitting in the boot while someone sprays a hosepipe over the car so you can track it in.

Mine does exactly the same, I think it's the rear light seals, and it has led to the first bit of actual rust on the car (I'm probably going to cut it out and weld it over the summer). It's less of a problem in my car though as I have stripped out the boot (and shortly most of the interior again) and have drilled a hole in each of the rubber bungs in the boot floor - that way if water does get in, it'll just drain back out again

yep will sit in the boot next test

I had a similar situation and found the 3rd brake light leaking water into the boot

cheers not sure what can be done, I've put some grease around it for now but still getting in.

I cleaned the back off where it seals against and added some silicone grease, stopped the leaks

Next is a new light or try and add a extra bead of sealant?

ok cheers