the best tips i can say with HIDs, is first mount them upside down, so the plugs face down. this seems to let them drain some. second, take some water sealant or even common Vaseline run int alone the crease of the box, once it is mounted. that should help it repel some water. i use clear sealant that drys, and it is working well in my headlights (bi-xenon) and in my fogs.