This is my next project, essentially following the process that 004Gunner used here:
Installed Rear Lights
They are going to be wired using a 3-position switch in the dash. One position is manual on, one position is on when in reverse, the third position is off. 004Gunner included a nice wiring diagram in his post.
So, mount outside toward the corners or inside behind the receiver?
Outside:
Inside: