1. transmission life is dependent on how well it was taken care of, specifically whether it was allowed to overheat, and how often it was shifted at WOT. They're good for well over 100K, but I don't know of many that have lasted over 200K.
zerothread?id=102300
I have 188K on mine and it still seems to be pretty strong. The first failure mode is usually refusing to go into reverse. The best replacement is a factory reman for about $3000.
zerothread?id=201739
3.
http://www.bgfindashop.com/locator/index.php
4. Try NICO's Infiniti Parts Forum first:
zeroforum/172 You might also consider polishing the lenses and then armoring them to prevent future problems.