Hi w209 japan, I haven't connected the paddles. To get them working you would need new steering column module parts and a new transmission control unit. Then you need to find someone(MB dealer with online access to stardiagnose) who is willing to do the programming for you.
All in all, you need a need TCU ~1300euro+ steeringwheel parts+labour which isn't worth it for me.
I don't have the part# for the parts, but if you want to proceed with this mod you can contact Steve,
mbenznl@gmail.com, he has the part# and can sell you the parts.
/Mike