I stupidly removed them from both cars without noting the orientation. One side has a sort of bulge and the lens is asymmetrical.

And yes, I tried the search function

P.S. And "lens faces down" is not helpful

The wire terminals point toward the center of the car.

I think the ribbed side of the housings go toward the front of the car.
The wire connections are critical.
The ground wire must connect to the terminal that's on the metal frame.
Otherwise the hot lead will short to ground whenever the light switch is pulled on.

Well, after a rum and coke and more careful study of the lights, I noticed the mounting holes are offset and they don't really fit right unless the ribbed side faces forward. Thanks for the help.

For anyone who finds this by searching, to add to Chris's statement about the ground, the ground terminal is the one closest to the outside of the housing.