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

stlsailorrv wrote:
The steep angle of the dash means I cannot mount it on the lower part of the dash.

A Tekonsha P3 (and probably others) can be mounted at any tilt (up/down) angle. I've got mine mounted pointing about 40 degrees down. Whatever you decide, you need to make sure the manual control is easily accessible, that's the first thing you need to get to if you get sway.