I had a 1988 Chrysler 5th Ave. Worst rattle ever. To fix it, I rolled up bath towels and stuffed them between the trunk lid and the car. Just put them where the weather trim is and slam it shut HARD. Fixed a lot of the noise. PITA to get the trunk back open though. I think rattle is one of the most annoying things ever, at least try to handle it, ya know/