It is called a Suppressor Cover, made by Bosch, lists for $63.00, but our friends at FastLane (this site) sell it for only $20.51.

It is found online in the Engine Electrical section, just below Starter drive in the list on the right.

Haasman

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)