The question is a bit fuzzy.
You can't sync the SanDisk via iTunes, but you can drag and drop MP3 files directly from iTunes to the SanDisk.
If you use Apple Music and only stream the music, you won't be able to save any data on the SanDisk.
What I don't know is whether MP3s purchased in iTunes can be copied to the SanDisk and played (DRM etc.).

Hello all
Does anyone know if it is possible to set the menu language to Italian?

Synchronisation via iTunes is not possible, but the m4a files can be transferred from the PC to the SanDisk via copy/paste. Works perfectly for me!

No, you cannot use I Tunes directly, but the songs are stored on the PC/Mac. You can copy them and save them directly on the SanDisk.

Hello.
If the music files belong to you and are on your device, you can use this tool, but it costs 9 francs: https://apps.apple.com/ch...

The advantage of the software is that the files end up in the same order on the device, playlists can be transferred and it syncs itself. Otherwise, you have to load the files onto the device in the desired order.

Is it possible to pair the Sandisc (or other BT enabled mp3 players) with the car radio via BT?

"all my music file is in itunes".
My sincere condolences!