I have a set of allen head sockets up to 10mm that get used almost every time I work on the car. Next oil change I am going to replace the oil level sender (and pump chain while I'm there-anything else?) and that oil sump pan has about 20 allen head bolts.
'02 C230 Kompressor
'89 560 SEL "Frau BlueCar" (retired April 2004)