I bought this car a few weeks ago and have been steadily making repairs since. The trunk leaks sometimes on the top passenger/right side (i.e. washing the car, or heavy rain with wind), leading me to believe it has little to do with the weather stripping or water channels.
I'm not a car person, but I've noticed some differences between the two hinges and bars.


Slight raise on passenger side, not flesh with rear quarter like other side


The trunk will close and catch, but you're still able to push down on right side


The higher up you look the more obvious it is. The underside of the trunk isn't being pulled down against the weather strips.



Driver's Side



Passenger Side



Bars are stabilized in the middle. Scratches on the ceiling, makes me think previous owner messed with them and the trunk.

I hope these made sense. I have little history on the car, but I know the guy who owned it before me did a lot of tinkering. I've already put money into to fixing the negative side effects, so I was hoping to maybe fix this myself. Thoughts please?

 

Welcome to the group. Sorry to hear your having an issue with a leaking trunk. I had a similar problem before, mine was the seam in the middle of the channel. The product they used to seal that seem, a type of rubber sealant cracked and that is where it was leaking. I put a bead of sealant, let it dry and my problem went away. Check it out.