landev-

since you've pulled it apart several times now, youre right, it may be more
labor intensive to seal. all the old silicone may just be getting in the way.
of course, we're presuming that water entry is only (?) via this seam,
although I'm not believing that all other possibilities have been ruled out.

suggestion to consider: there is Nissan butyl sealant which is a gray, non
drying putty which can be rolled out and stuffed into the groove. sofens
when heated, and molds into the contours. if you have easy access to
Nissan dealer, I can get you part#.

after this is done (or even if not) continue by replacing outer lens. then (!)...

use windshield sealant. it is more viscous than your generic RTV silicone.
after windshield sealant has dried, then go with thicker RTV silicone.
the rubber rand just helps the water coming from the road but really not
expected to keep all water out.

i'm sorry to learn that you've had to spend so much. car ownership should
be fun and not a wallet killer. if you continue to have problems with the
lights, email me for more ideas. r-

__________________
-- raymond~
47º 34'N 122º 18'W