Thanks Newbie; that's pretty much what I figured from looking at the exploded diagrams on Toyo.DIY.
It would be quite a P.I.T.A.; the headlining would have to come out; and brackets for the opener custom fabricated & attached to underside of roof. (assuming that is; that there's actually enough space btw the SX pillar & headliner for it to fit.
Even then you would probably have to repaint to the duco on the roof because of damage caused by heat transfer from the welding process- unless that is; you have a lot of faith in JB Weld).
The other issue is that AFAIK
; the opener directly actuates one of the door hinges; so you would have to adapt an RX hinge. .
Now; if you had a (hell of a lot) of time on your hands and got this far. . . you would THEN have the issue of mounting the LH & RH sensors; which (from Toyo.DIY diag.) seem to mount onto each edge of the rear glass / door pillars. I figure the chances of these RX sensors fitting into the SX back door with an OEM look to be 2/5 of F.A.
Apart from this I had to peel away the leading edge of the headliner when fitting the rear camera. It seemed to be glued in & didn't pull away easily - it seemed to me that you could easily damage or even destroy the headliner trying to get it out if you weren't very patient / careful.
I think I've answered my own question here - it's all too hard. Might look again at the feasibility of replacing OEM struts with Linear Motors.
I might check this out closer to Christmas (our Holiday period) when I've got a bit more time on my hands. . .