Step-by-step installation with short comments:

Set of parts from ebay:

Holes in carpet and body for bluetooth unit:

Unit without cover:

And with cover

Wiring to headunit (power, voice and canbus):

and to the front inner lamp for microphone:

Install microphone in lamp:

Assembling, programming by VAG COM and see new menu:

Inside phone menu:

Call:

Headunit is muting on call:

These are the part numbers, provided by TallioN.

Central unit - 5P0 862 335 C

Antenna - 8P0 035 503 E

Microphone - 3B0035711B

Holder - 1Z0 035 815

Cover - 1Z0 971 813 62U

socket for bluetooth unit - 4E0 972 144

socket for radio - 3B7 035 447B