Radio stays on when ignition off

[Nibbs]

I think I've narrowed down what the car (95 X300) is doing when it
shouldn't be doing things - radio stays on, seat still adjustable
up and down and mirrors adjustable, all with ignition off

Am I correct in thinking it should not do any of these things?
(Incidentally, windows don't work with ignition off)

I'm guessing from the circuit diagrams it's a stuck ignition relay
under one of the rear passenger heel boards, but unsure which one -
would anyone confirm my suspicion and advise? Any other
possiblities or suggestions?

Many thanks

Chris