Have we met? I was in Austin to meet a few NSX'rs a couple of months ago.
First off, I would take the bulbs out, and use a shop vac or even a hair dryer and get all of the moisture out.
Put the bulbs back in, and see if it happens again. If so, repeat the shop vac/hair dryer step, then take some 100% silicone, and rub with your finger along the joints from the mold process (may be where water is getting in) and see if that helps.
As an absolute last resort, you could drill some very small holes in the lowest part of the light, out of sight, to allow air flow, and water drainage. If that doesn't work, upgrade to an 03 set!!!!