220 589 00 99 09 Adapter line - WS54.00-P-0050-09B
WARNING: This page is about a different car, the 2011 Mercedes-Benz C350, 2010 Mercedes-Benz C350, 2009 Mercedes-Benz C350, and 2008 Mercedes-Benz C350. However, it is still accessible from the selected car via links, so may be relevant.