Easytiger, are you following me, or am I following you? (laugh)
The YF-12 didn't have anything in the back seat, there wasn't a back seat to put anything in. It did have a fantastic electronic suite, though. Included were a comm radio that was all but totally invulnerable to interception because of its rapid and seemingly random frequency shift but it often lost sync with the ground station, could not be reset in flight. A later development is currently in use, referred to as "Frequency agile." The AFCE system was fantastic, even current "RNav" systems don't have its capabilities. (Sorry - Automatic Flight Control Equipment) It could be programmed to operate the airplane from its parking spot, taxi to the runway, take off, fly the mission, fly back, land and park the plane, all without operator intervention. All you had to do was start up, and later shut it down. Or that's what the boys with high foreheads said. The truth was that the systems would all drift to a greater or lesser extent, the longer the mission the greater the drift. So if you wanted to hit the runway, and not land a half mile out or to one side (Always got the heading right) you had to babysit the AFCE. Or hand fly. Current (military) systems much better, many current civil autopilots do have an "Auto land" system, but FAA regs say aircraft will be hand flown for landings.
Regarding the "Other" things, I don't know what the current classification is so to be on the safe side I will continue to say nothing.
As a side note, I just checked at Amazon.com, they have 19 listings for Joe Poyer's first, and in my opinion best, novel. The title is "North Cape." The first chapter shocked me when I read it, made me think he had been flying sleds in the 60's. Read that and you'll have a very good idea about the "Other." Read the rest of it too, it's a good adventure/survival story set in the far north.
Enough for now.

Take to the air, but only with a pair!

WLR