By Joseph Little (June, 1997)
All P1800s have the problem of not draining water out of the trunk gasket area after a rain or a bath. Over time, this water will cause the gasket to rot, and the water to leak into the trunk, causing damage to that, as well.
A cure for this is rather simple, but may require a prescription in some states. First, you need something that can sit flat in the gasket tray that will also allow the attachment of a small hose to the bottom. I used a hypodermic needle, without the needle. Next, drill appropriate-sized holes in the tray to fit the needle or whatever through. As this area is prone to getting wet, be sure to prime the drilled areas with rust-proof primer.
Fit the fixtures through the holes and seal them with silicone. Now, fit a small hose to the end of your fixture, and run it behind the trunk lining, down to the hole for the rear bumper. This works for all but the most flood-like rains, and prevents the degeneration of the hard-to-find trunk lid gasket.