The links below are for the combined WIS and Service Bulletins to do a COMAND 2.0 Navigation head unit retrofit on a W203 "C" Series and the retrofit publication on benzworld.org.  The publication was written for my 2001 C-320 Sedan but should "virtually" be the same for all 2001-2004 W203 models.  I have also included a link to another COMAND retrofit page that proved very useful for my retrofit.  You can also contact Steve Krabbenborg @ MBenzNL who is way more knowledgeable than me and sells and retrofits COMAND units all the time.

WARNING:  There is a rash of G-Class (A463) COMAND units being sold on eBay advertised as directly compatible with W203 and W209 Mercedes, but this is not true.  The A463 units will fit and can be made to work but there are two issues with them.  The easy one is the gyro adapter (grey) angle is wrong for a CLK or C dash.  It needs to be replaced with a “yellow” (25 degree) adapter.  The more difficult issue is the A463 COMAND does not receive speed data through the CAN wires and needs a separate VSS wire run to C2-6 from under the hood or it will not read and display vehicle motion.  Unless you are ready and knowledgeable enough to do the above, make sure you are buying an “A203” part numbered COMAND unit and not an “A463” one.  Or do the right thing and buy one from Steve which is guaranteed to work!!  You will save a lot of time and money buying one from him.

I added the COMAND Manuals download page link on the left.  It includes most models between 2001 and 2005.