This article is from the Chrysler-Plymouth-Dodge FAQ, by Dr. David Zatz with numerous contributions by others.
Tim Drake fixed his 1987 Sundance trunk leak by taking the light cover off
and treated the gaskets and drilled small holes in the bottom of the light
covers, so the water could leak out the bottom.
From: (e-mail address removed) (Wade M. Goldman) fixed the water in his
trunk and right tail light assembly (which caused on tail light to be
dimmer than the other). After replacing the light socket he corrected a gap
between the light assembly moulding and the car with RTV silicone.