Filling the fuel tank is the cause? Are you outside of your mind? I paid 35k for this Maverick, I didn't finance it, so yes I expect Ford who's has manufactured engines for over 100 years to have this solved. Excuse me.
I noticed the same thing, the passenger side is protected with a plastic housing, it 's not part of the cubby though. I believe the drivers side is open because of the muffler, heat issue. I sprayed fluid film in there and will be installing mud flaps.
So I washed the salt off the truck. I drove to work and I park inside a large garage, I needed something out of the back and left the the rear doors open for quite a few minutes. When i came back I noticed puddles on the floor on both sides. So when the the doors are open the water comes out...