Bonjour from France
I come here to share my experience with auto folding mirrors on RX400H MY2008.
I bougth a pair of Po-40 in Australia from Michael aka Ashpoint (details in this discussion)
I saw a old document explaining how to do it on RX300 and decided to take the risk...
To make it short:
it works perfectly,
to install the driver door: 25 minutes (45 for the first time on passenger door).
the document for RX300 was usefull : no diff compared with RX400H, but there is an important missing info in this doc: where to attach the black wire...
here are some pictures showing details
3)remove screw 1 4)remove screw behind door handle 5) unclip all around the door 6) remove the panel, detach all connectors. 7) lock connector: connect on red & white wires the blue and white wires from po-40 8) armrest connector a) attach red wire to big green wire (+ Batt) B) attach orange wire on orange wire (+ acc) c) attach black wire on big white/black wire (ground) left side: right side: 9) on the cable from the side mirror, cut green & blue wires and solder them like on next pict: 10) I used some scratchy thing to fix the po-40 11) and here is the final install
(of course I attached cleanly all the wires)
of course I attached cleanly all the wires.
Now, when I lock the doors, the mirror are folding
and they unfold when unlocking.
et voila...