on my 85 I had it BAD. It was coming in from the taillights, and the triangle windows. I bought a roll of butyl tape and resealed them both. That was in 2002. I saw the car in the junkyard last year, so I dont know it held up over the years. It did work great for the year and a half I owned the car.....
I thought the redesigned lights were designed partially to better help keep water out? The only way to know is get into the hatch, shut it, and have a buddy run a water hose over EVERYTHING. Chances are, youll find it..
good luck