Noticed that i do not use CD/Radio unit often and bearing in mind its rather big volume i decided to remove it completely and make a better use out of the middle panel. For example putting GPS there.

My only question is - does it affect anything if i simply disconnect the CD/Radio unit from the car? Can there be any error messages because main computer can not find radio?

Thanks in advance!

The radio is a NODE on the CAN, so if you remove it, the mileage (kms for you) display will continually flash. You can stop the display flashing by carrying out the Proxy Alignment procedure with Fiat Examiner or the registered version of Multiecuscan.
.