since we're talking rear head rests ...
when i got my car it did not have rear head rests but a pair of kenwood speakers fited in the indents (unconnected, but that's another story ...)
i have the switch on the dash that would activate the headrests so i assume it must have been fitted as standard but removed to house to PO's sound system.
Anyway, i do not have any traces of any hardware under the rear parcel shelf (or hat tray as it was referred to by some euro users ...) apart from a number of mounting tabs that does indicate that some devices were removed. When i press the dash mounted swith i do get a click from somewhere at the back. I also have not seen the plastic inserts where the headrest's 'legs' pass through to go underneath the parcel shelf.
my real problem is that i do not know what was removed, what it looks like, what the part numbers are, etc. to attempt a retro-fit - if at all possible ...
since u guys have been probing around in this environment can u please provide me with some pointers / feasibility ?