Where to mount a brake controller in a 2014 Toyota Sequoia?

I had the Tundra which is basically the same dash and interior up front. I mounted mine into the plastic where it wraps under the dash, above my right knee. Two self tapping screws hold it in fine and if you ever remove it, you won't see the screw oles. You want it in a position where you can quickly get to it in an emergency. If you have the Tekonsha Prodigy, you have a lot of options in terms of angle as to where you can mount it.