I noticed that the WRX have a nice fog light/hitch light. I was wondering, can you install that same light into a 2016 Subaru Impreza? I see that there is a square for a possible hitch?

That block-off in the rear bumper is for the rear fog light in other markets. I have seen write-ups where people have gotten the part from japan or the UK, and retrofitted them, but it's not as simple as one might think (to be wired correctly, they should be wired to a separate switch, which is not present).

 

I've also seen a company that makes hidden hitches that utilize that same opening. That's pretty cool!