Yup, there has to be a connection somewhere there for the T for the brake light pressure switch. I see they don't show that on their pictures. In the picture the "brake failure" warning light connector is in the middle, accessible and facing the drivers side of the car looking at it from the front of the car.
I think all the units that I got off those cars have that mounting bracket with the two threaded studs on them. So one could drill a couple of holes and mount them. Me, I am trying to keep from drilling more holes, so I liked the idea of tucking that sucker underneath and out of the way. Or just mounting it like they did in the first picture. Along side of it, and down some..