Tail light vent holes

[Dave W]

The standard caterham tail light mounting position has the vent hole on top Vs on the bottom side of the lens. What is general practice, Should I keep it vented, will water make it's way in the housing or should I seal the vent hole off.
Thanx Dave

[Dave W]

Found on the UK Lotus seven site. They recomended that you seal the top and actually add a drain on the bottom of each lens. Dave W