Back-up light relay locat0?

I have a 2008 base model (no nav). I'm trying to install a third-party backup camera and mirror/display. The kind that covers the original rear view mirror. The mirror portion has one cable for 12V always and another cable for 12V when the transmission is in reverse.

The 12V always is obtained from a fuse tap in the interior fuse box. I see that apparently there's a back-up light relay with a red wire that looks like a good source for 12V for backing. Where is the darn thing? I got a two day subscription to <can't include URL) and if it's specified there it's very well hidden.

(Has anybody hunted down the person who designed that fuse box and forced them to change all the fuses in that box on the side of the road in mud and pouring rain?)

(I got the wireless setup figuring it would be easier to install. I was wrong. There are ones that only require connection at the backup light, and routing a cable from the rear to the front can't be worse than that fuse box.)