I noticed this on my '03 MINI MC
after tower bushing replacement, also. Got a squeek when turrning the
wheel, mostly in the cold, and mostly on turning quite a bit one way or the other.
I took off the top bolt and used some liquid wrench silicone spray a few times, and it eventually went away.
It's probably the rubber vs. the shock tower metal and varying tolerances.
Same thing with my wife's 2001 VW Cabrio the when we replaced shocks and shock tower bushings.