I keep getting water in the spare tire well. I suspect that the tail light seals need replacing but it is not obvious to me how to get to the taillight assembly for removal.

 

If you open the flap in your trunck like you would if you were to change the bulbs, you should be able to locate four 8mm gold nuts. Remove those four nuts and the connector, then push the assembly towards the rear of the car to remove the light.

 

i have this same issue

 

I got the same thing with my 96

 

This was the worst issue my '97 TL had when I bought it a couple of months ago-- the water had been flowing into the trunk compartment for years and long enough to rot out the tire comparment (so badly that when I used a hammer to break up the ice, I knocked a hole clean through it). Considering the hole, I thought it best to leave it covered with a rubber backed car mat allowing the trunk to drain and not fix the hole until I traced the source of the water.

I traced the problem to the passenger side tail light thanks to an ice flow from the tail light all the way into the tire compartment.

Finding the three gold nuts was not a problem. Getting them off was a bit of a challenge- the treaded attachment posts sufficiently long to make a standard socket problematic. But I eventually removed the three gold nuts and disconnected the wiring (quick detach).

Performing this operation out doors and in freezing weather, once I had the tail light assembly out, I found ice in it. So I had to warm it up, melted the ice and I blew most (but impatiently not all) of the condensation out of the assembly with a hair dryer.

I purchased a GE (General Electric) outdoor clear silicone product, cut the application tube at the fine bead point and then laid a fine bead of silicone between the edge of the plastic assembly and the rubber (appeared to be neoprene similar to a scuba wet suit) gasket, then also laid a fine bead of silicone between the two plastic halves (lifting up the rubber flap) along the top of the assembly and down the side. Before placing the assembly back into place, I cut back the silicone tube to the thick bead point and laid a heavy bead of silicone between the rubber gasket and the metal of the car, and replaced the assembly and tightened it up.

That was two weeks ago and since performing this operation I have not seen any evidence of water intrusion into the trunk compartment.

This took me less than an hour to do and I am only moderately mechanically inclined.

 

Sight Unseen (and others): same problem with my 98. condensation in passenger light assembly, a lot of water in the spare tire well. Looks like an excellent project for me this next week.