Having been bitten by the bug of retro-fitting in my Rover 75 days, I have to say that the S Type is an ideal subject for such things, as I further confirmed today when 16 function memory, heated seats were fitted and the whole job, including the rear seats as well, took less than an hour, with no setting up and no wiring to do B)
Talk about plug and play
Powered rear window blind and headlamp wash are next on the list