I mounted a brake controller in my wife's 2007 Expedition last night. Along the bottom of the dash beside the emergency brake pedal, I found a place that the bracket fit perfectly. Almost like it was intended to go there. I used the screw that holds the plastic to the metal edge to secure one side and drilled another hole to hold the other side of the bracket. There were ample places behind the dash to zip tie the extra wire to. The controller is up out of the way, but it is still accessible when needed. My wife even said it looked good in that spot

If you would like to see some pics I can get you some when I get home from work.