Thanks Old,
No not new, I put a new one in years ago, then spent a couple months chasing down leaks. The tail light assys leaked, the area under the rear window on both sides leaked, side marker leaked and the seal leaked at the joint. I put the ends at the bottom and glued the ends together. No leaks for 15 years. Then I had the seals of the panel under the rear window repaired and re Painted. The trunk fills up pretty good and drips where the lap joints are. Seems the water is getting under the seal and dripping in at a low spot where the lap seam is, not through the seam. I got some Permetx adhesive but that is contact cement, have to put it on both seal and groove the press together. I'll try for some 3M black, I think that's more like butyl rubber. A very thin film all around the seal channel may help.