[bahman]

I have had the same behavior on my 2002 C4, and my Indy or two dealers could not identify any cause. My issue occurred at full turn lock, on cold surfaces or smooth shiny surfaces like garage/shop epoxy floors. I learned to adjust and accept it, and avoid it by not turning the wheels to full lock.

Hopefully, the thread you have started here can lead to a plausible explanation or solution.