I was lucky enough to win an 8p cruise control stalk from a 2009 A3 on ebay last week. for 99p!!
I fitted it this weekend.. not too difficult. then recoded the engine and steering wheel in VCDS, and it works!
I didnt have the lower steering cowel.. so I modified the old one with a holesaw, luckily I had one exactly the right size.
You can barely tell its not a factory part.
So I'm pretty happy, cruise control fitted and working for 99p!