Whenever I wash my 1971 142, I accumulate water in the trunk in the wells behind the rear wheels. The trunk has a new gasket and I have smeared the gasket with silicon grease using the grease imprint on the matching body face to confirm that the gasket has a good squish contact area with the body, so I don't think gasket leakage is the problem. I initially discovered that the seam sealant on the ends of the drain box under the rear glass had separated and was allowing significant amounts of water to enter the trunk at those points. I completely removed all the old seam sealant and resealed and that area now remains dry. That greatly reduced the amount of water; but, I am still accumulating about 10 - 15 ml of water in the well on the driver's side each time I wash the car. The passenger side is remaining dry. The water now appears to be entering from somewhere around the taillight area or the back edge of the trunk over the taillight; however, after repeated poking around forays and sealing likely locations, I have not been able to suss out the location of this final leak. Does anybody have any suggestions as where to check?

Full disclosure, I do use a pressure washer; but, with the pressure turned down.