What are the steering wheel controls on the S4's?

[TheHoff]

Been looking at a lot of S4's on Pistonheads and here, some have steering wheel controls but I am not sure what they are for.

I believe that the left one is for a bluetooth phone operation but not sure of the other... stereo volume?

I presume that these were just factory options bought at the time of the car?

[xyber]

Menu scroll
RNSE Mode select
Phone answer/hang up
Vol up/down

(I think?)

You can retrofit, you need...

Steering wheel
Airbag (B6 is single stage, B7 dual stage)
Loom
Slip ring
Correct control module
Recoding

Probably looking at £7-800 DIY with a 2nd hand steering wheel

[TheHoff]

I considered retofit but I think it would be easier to find one in the first instance with it fitted to save the hassle and expense. To be honest I think I could live without it but its nice to know the options before purchasing.