c220 2012. Estate water leak

[tonygt3]

Boys i am finding water ontop of the cover in the back of my estate. That is the screen cover that pulls out from the seat backs.
Obviously i have a leak at the top of the tail gate. Yet it feels quite dry at the roof level. No roof glass.
When i open the tailgate a little rain water does drip onto the cover.
My Windows do have a lot of condensation.
Yes my car is in warranty but it took four months for Merc to fix my wiper auto unit, as in a lose connection that they had not bothered to look at. So i do not have much faith in OMC.

Is this a known fault with a simple fix ?

[tonygt3]

thanks Jim, yep I posted here in case it was a common problem, obviously not.
Car left out last night, a bit of rain, water on boot cover (not a lot).
The rear of the roof at the tailgate feels damp.
I have checked the rubber conduit hose fittings which appear tight.
good point the roof rail mounts.

[tonygt3]

No Dan, I never did get to the bottom of this.
sold the car at the start of the year.
I also looked at the fancy aerial fitting