IF you have a sunroof, clogged drain is likely the issue. My 04 EB does this exact thing if I don't clean the channel and drain holes frequently enough. Looked into the leak with a borescope and I see that water runs over the channel edge and makes its way over the headliner and down the A pillar until it finds a place to exit...which apparently is the grab bar. My parking spot leans slightly to the driver side so it's always the left grab bar.
Seems that the Expy drain holes are smaller than my other sunroof vehicles and it doesn't take much to clog them...although that may be better than allowing the trash to go down the tube and clog it further down the line. I have never had to blow out or rod out the drain tubes.
I find that keeping the sunroof gasket lubed with Kryton swells it a bit and reduces the amount of water/trash in the channel. 17 years with all original components.
Have never had a roof seam leak or resealed anything.
This Expy has been outside all of its life in central Florida and SE Louisiana so it's had high amounts of sun and rain.
Hope this helps.
