When doing replacement or upgrading on 1994 – 2005 Mercedes-Benz C220 C320 capsule halogen headlamps HID with, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

High Beam and Low Beam Headlight 1994 – 1996 9003
Front Fog Light 1994 – 1996 H3-55W
Back Up Light 1994 – 1996 1156
Brake 1994 – 1996 1156
Dome Light 1994 – 1996 578
Front Side Marker 1994 – 1996 P21/5W
Front Turn Signal 1994 – 1996 P21/5W
License Plate 1994 – 1996 6418
Parking Light 1994 – 1996 1157
Rear Side Marker 1994 – 1996 12821
Rear Turn Signal 1994 – 1996 1156
Glove Box 1994 – 1996 DE3423
Inner Tail Light 1994 – 1996 P21/4W
Interior Door 1994 – 1996 DE3423
Outer Tail Light 1994 – 1996 12821
Rear Fog Light 1994 – 1996 P21/4W
Trunk 1994 – 1996 6411
Low Beam Headlight 2001 – 2005 H7
High Beam Headlight 2001 – 2005 H7
Front Fog Light 2001 – 2005 9006
Back Up Light 2001 – 2005 1156
Brake 2001 – 2002 1156
2003 – 2005 1157
Dome Light 2001 – 2005 578
Front Side Marker 2001 – 2005 12961
Front Turn Signal 2001 – 2005 1156
License Plate 2001 – 2005 12844
Parking Light 2001 – 2005 194
Rear Side Marker 2001 – 2005 12821
Rear Turn Signal 2001 – 2005 PY21W
Tail Light 2003 – 2005 1157
Glove Box 2001 – 2005 DE3423
Map Light 2003 – 2005 6411
Trunk 2001 – 2005 6411
Low Beam Headlight 2001 – 2002 D2R
2003 – 2005 D2S
High Beam Headlight 2001 – 2005 H7
Front Fog Light 2001 – 2005 9006
Back Up Light 2001 – 2005 1156
Brake 2001 – 2002 1156
2003 – 2005 1157
Dome Light 2001 – 2002 578
2003 – 2005 6411
Front Side Marker 2001 – 2005 12961
Front Turn Signal 2001 – 2002 1156
2003 – 2005 2357
License Plate 2001 – 2005 12844
Parking Light 2004 12961
2001 – 2003, 2005 194
Rear Side Marker 2001 – 2005 12821
Rear Turn Signal 2001 – 2005 PY21W
Tail Light 2003 – 2005 1157
Glove Box 2001 – 2005 DE3423
Map Light 2003 – 2005 6411
Trunk 2001 – 2005 6411