Thanks, Y2KMondeoSVT!
I had a peek between the roof and roof-liner from the back of the car (after removing the two mushroom clips), and there does not seem to be any wiring for a rear dome light there, just the metal frame to receive one, though (judging from the picture I saw for this modification on the Mondeo Enthusisast Group site, or was it Mirez?). I have the moon-roof (yeah, I already mentioned it in heading; must be age catching up with me ...

), so routing the wire might be interesting.
Again, "Candaian specification" cars can be sometimes quite different from US-models. An example was my built-in-Canada 1980 Pontiac Catalina, which was really a Chevrolet Impala under a Pontiac skin, complete with a small-block 4.4L engine (anyone care to remember that dud engine, with all of 120 HPs?

).
A last one while we're at it: is the D79 connector something I could ask just like that to any Ford parts-person, or is there another more exotic designation for this part?
Again, thanks a million for your help, it is much appreciated!
Serge