Nissan: Trunk wet - 2001 Sentra - NOT the taillight

There is water on the right side in the trunk of my 2001 Sentra. To date, I
have done the following: (1) Sprayed with a garden hose. Saw a little
water enter around the taillight. Took taillight out and "re-gooped" it.
Anyway, that's not it; in a rain when the trunk gets wet, the taillight
area is not wet. (2) Thought it must be the the backlight (back window).
Took it to Auto Glass Specialists, who replaced it a year and a half ago
after a vandal attack. They took a lot of time with it, and concluded
(taking good time to let me see it) that the water wasn't getting in the
window.

The water appears to be entering where the right rear wheel well joins the
outer fender, about 1 inch or so above where the trunk floor joins these
pieces. It's very hard to even get a hand in there, much less see it, much
less get in there to repair something. Can't see it from the outside very
well either. It's beneath the point where the plastic bumper fascia joins
the fender. I may try jacking it up, taking the wheel off, and sticking my
head in there to see it from the other side. Before I goop up the area with
'undercoat' (and then in all likelihood find I have not solved it)... any
recommendations?

Anyone else have this problem? What did you do to fix it? This car is only
2 years old so I don't see or expect it to be rusted out.

Thanks in advance ---Pete

"Sarky" <com> wrote in message
news:1rZEb.36786$videotron.net... 

Yep. I'm going to do that... when the weather is warmer. It'll go through
salt season though. Sure don't want to do this in freezing weather and
anyway the repair materials usually aren't recommended for use in cold &
wet. When it gets warmer, I'm going to remove the bumper cover, spray
around until I'm sure I've found the leak, clean it up on both sides and
remove any rust as well as possible, then goop it up and paint it.