IMHO, The best, and most unobtrusive, Brake controller is the DirecLink.
DirecLink Brake Controller - DirecLink.com
I ziptied the network computer module under the dash on the footbrake frame, which can be seen when you remove the footwell cover. I then use the supplied coiled telephone cord to connect the ECU to the control unit. Took me all of 15 minutes to install it.
I use the alternative mount to stick on the windshield just inside the A pillar and above the dash. This way the controller itself is right to hand and you can see all the functionality at, almost, eye level.
Alternative DirecLink Mount
When not in use, I remove the suction mount and controller and just stuff the telephone cord under the foot well cover.
No drilling, sticking, velcroing needed for any part of the system. I can heartily recommend the DirecLink system.
No association with the company, just a very satisfied customer.