For retrofitting multifunction display only need suitable switch stalk and three wires. You can see inside the red box in the diagram.

Reset button, Ambient temperature sensor, Multifunction indicator, Onboard supply control unit, Dash panel insert
E91 - Function selection switch
E92 - Reset button
G17 - Ambient temperature sensor
J119 - Multifunction indicator
J285 - Control unit in dash panel insert
J519 - Onboard supply control unit
J623 - Engine control unit
K - Dash panel insert
T2fm - 2-pin connector
T32 - 32-pin connector
T41 - 41-pin connector
T73b - 73-pin connector
110 - Earth connection 2, in dash panel wiring harness
269 - Earth connection (sender earth) 1, in dash panel wiring harness
354 - Earth connection 6, in dash panel wiring harness
439 - Earth connection 3, in dash panel wiring harness
605 - Earth point, on top end of steering column
606 - Earth point, under the centre console near gear stick
B383 - Connection 1 (powertrain CAN bus, high), in main wiring harness
B390 - Connection 1 (powertrain CAN bus, low), in main wiring harness
T41

More images about T41 connector here (thanks Der Finne
T32

More images about T32 connector here (thanks Gannu_1
More info here: http://www.uk-polos.net/view ... 70#p466570
VCDS
Instrument---Byte1---bit3


