Actually, for Sony radios you can get an interface that will work with both the stalk and the display.
Connects2 carries them, parts no.
CTDPGS002 for semi-multiplex cars, and
CTDPGS003 for later full-mux.
I haven't tested them personally, but there's no reason they shouldn't work. You need to keep in mind that the headunit should have both the mini-jack remote input, and the Uni-Link CD changer socket.