Hello to all

I'm an Italian user, and finally I found a forum that speaks completely of my car.
I would like to apologize in advance for my bad English.

go to my problem.
I am the owner of a VECTRA 2003 (half CANBAS). My audio system is a "NCDC 2015"
Unfortunately, the cd does not work anymore. And the CD player has a problem with reading CDs

I would then replace it with another without losing radio steering wheel controls and trip computer.
I am also not willing to change the radio, only if there is a way to read the mp3.

I have read various possibilities. What more would suit me would be to connect an interface that let me read the mp3.

Unfortunately I know that the NCDC2015 has an AUX input.
You know how I can create it?

Otherwise you could advise me some other method or another product? (NO TUNER FM)