Problem Steering wheel turning noise in place


I recently purchased an A4 cabrio from Germ and I have the following problem:

ex: when I park and take the steering wheel straight to the left, a strange fff noise is heard from the front wheels ... as if something is hanging ...... you say something is breaking ....... the noise is not strong ....but it obsesses me

P.S. the noise resembles that made by a sheet hanging on something.... when the steering wheel is fully turned, it is heard about 2-3 times....

do you have any idea what's going on?