I have two problems with water. One is a water sound I am getting from the motor area. It sounds like water splashing around. The other is water is getting into the trunk and I cannot find a reason for that.
What kinda caddy is it? STS or Seville(same car), you need a new trunk weather strip, remove the rear tail light assy, put some clear silicone on the holes and reassemble, remove the black peice on upper trunk part there are 3-4 screws, under rubber lip, apply silicone to thoes screwholes, also remove trunk liner, let it dry, spray some mold stuff on them, or buy new, get some spray rubberized coating and spray the innerwheel wells( inside the trunk), you will see holes or lite from the outside, looking from inside the trunk, in both sides down by the bottom, cover it a couple times( it has to be dry)