I just bought a unit of C200 CGI avantgarde 2011 on March 2011.
I has been driving 3 generation of C Class, expecting this new CGI model should be the best among all, but turn out to be.. , just to share with you all the problem I facing:-

1) 1st time using wipe found out terrible noisy during wiping,
Visited workshop they tried clean the screen, cannot solved then they
replaced new wiper but turn out to be the same.
Drove back, they adjusted the fitting angle, now 80% ok.

2) Complaint when in reverse gear and driving at low rpm 0 ~ 15km/hr, the
engine sound like pur..pur.. (like driving speed boat) and another sound
from the back tat..tat.. appeared.
MB changed the purge valve and re-position some piping,(said that 1
pipe too close knocking at the body.
Even though changed purge valve, but the pur ..pur sound still remain
during low rpm until now.

3) At 2xxx km mileage, the whole undercarriage sounded likes 30 years old car, MB checked and changed 2 new front suspension, given reason was the 2 front absorber has been spoiled.Problem solved after replacement.
But after a week, the whole undercarriage sounded even terrible than before, MS checked found out the whole egine metal cover dropped down due to no enough grip of the small screw, changed a new bigger screw.

4) Complaint very bad sound proofing, MB said nothing they can do

5) No facing stalling so far, no doubt from speed of 25 km/hr above is a good car, good handling.

6) Still annoying at the pur..pur.. sound when driving at low rpm especially during traffic jam

hopefully can get some advise from you all to get to the bottom of these whole problem. FYI, my car now only at 3,500 mileage. Thanks