Mercedes-Benz MY2001 C-Class COMAND 2.0 Instructions For Use Manual page 10

If you are going to install the AUX port in the glove box now is the time to do so. There is a knockout port
on the right side of the glove box opening like pictured below:
Remove it and install the AUX connector (refer to the "G" class install WIS) which will look like this
installed in the glove box:
I then routed the AUX cable under the glove box with the GPS coax and into the center console opening.
Make all the connections to the back of the COMAND unit and test to make sure everything works before
buttoning up all the stuff you removed. Everything is reinstalled in the reverse order they were removed.
Make sure you follow the WIS to reinstall the center air vent assembly.