I need some help here, I have an 88 260E and water is getting into my trunk area. I cant find where the water is coming from, I have checked all around the rear window, the trunk seal and even resealed the lock and trim on the trunk lid.
I think it may be because of the sun roof drain but I am not sure where it goes and there is no leaks in the passenger compartment.
Because of this there is a lot of moisture in the car and I think it may be messing up the computer if it is inside because now that it is raining the car dies sometimes for no reason but it does start back up after cranking a little.
Please help!

 

on the left side of your trunk between the rear window and seal for the trunk you have a body seam they leak somtimes. best way to tell is to have somebody jump into the trunk with a flash light and have somebody hose down the car with a water hose the person inside the trunk will able to see any leaks. remove interior trunk panels if needed.