how does the multifunction wheel talk to the radio?

[duncanhancox]

just planning rns-e retrofitting into a b5 a4 - the car doesnt have multifunction steerwheel.

im wondering how the wheel talks to the head unit? is it the can-bus or dedicated wiring

can i retrofit a multifunction wheel and how would i wire it up?

thanks for any info

[Dippy]

CAN bus, however not directly: It needs a module which is located in the relay area above the pedals.