Self-installation Free-speeching equipment

Hello together, bought me a fixed-fit hands-free device and would like to try the installation again. Now the part is not there yet and it is still possible to get some information in advance… I have a few questions: 1. Where does the black box belong exactly? In the center console under the radio or could you put it in the telephone console? 2. In the interior lighting (the black plastic border) a kind of ventilation slots are inserted as dummy/deco. On the right side you can see under it a recess with a rubber plow. I think the micro is sitting when a phone is installed ex factory. Is it possible to accommodate the retrofitted micro there, if yes, how do I get it – so how do I take the ceiling light out and how do I guide the cable through the piece of sky from the front window over the rear mirror? Thank you for your efforts, Greeting Michael