Their seals leave a lot to be desired, but at least the newer styles are using a foam seal instead of butyl tape & caulking...
The problem is the assembly. I got to looking at one of my rear clearance lamps, and discovered:
(look closely at the bottom edge)
(keep looking....)
And this is how it wasn't sealed:
And I'd been spraying water up that direction for 2 1/2 years... fortunately the wiring feeds into a horizontal aluminum square-wall framing member. Who knows how much water migrated in, but so far I've never seen any damage as a result.
