Today I fitted my brake controller ready to be wired up on Monday .
I opted to fit it in the aperture behind the door in the R/H lower dash that allows access to the fuse panel and the little knickknack drawer . I put it there because I didn't want to drill holes in the dash and its a very easy fit .
I made up a couple of simple brackets out of aluminium , as you can see in the pic there's not much to them . They sit at an angle because of the angle of the dash . I then drilled a couple of small holes inside the aperture to mount it , these are covered by the door when the controller isn't being used .
The controller sits up at an angle to give a pretty good line of sight when you are sitting in the seat and as most of it is in the aperture it doesn't protrude too far out from the dash . In all its a very easy installation that allows you to remove the controller quickly when you're not towing by removing 2 screws and the door / knickknack drawer can be clipped back in place to cover the 2 small holes .
I used a Tekonsha P3 which is an easy fit with plenty of room each side in the aperture , other brands of controllers may be physically larger or have different mounting points .
Hope this helps you if you're looking for somewhere to mount your controller .