As far as I know they did not come with any, the dealers installed them. Quick search first before posting is usually best Fernando. https://www.ferrarichat.com/forum/threads/348-oem-radio.495078/
I bought a Becker 6105 for my 348. Becker radios were originally installed in the Ferrari 360 and 430. I thought this was the best alternative for the 348. Got it on Ebay from a seller in Lithuania, as good looking as brand new. It looks like the one on the pic which is Becker 6106 with NAV (6105 has no NAV). Image Unavailable, Please Login
So elegant in its simplicity! Most car later versions of car radios had/have too many buttons for me... I can't see as well as I used to.
To answer the OP, as far as I know none of the cars came with OEM radios. Dealer or owner installed aftermarket. I've seen about every unit in 348's that we popular among luxury cars of the 90's. Alpine seems to be more numerous, but certainly not exclusive. I can't even remember what my car had before I yanked it. My Spider had an Alpine, IIRC, but I don't remember it working very well at all.
I use my phone for Nav and blue tooth it to the head for directions out the speakers myself. BT is absolutely standard on most radios now days. I have to hand it to you, you got what you were after, to each his own I say.
The end goal is to write android apps to display O2 wide-band data, engine info, and help tune the standalone ECU.
Makes sense. Sort of. Every wide band out there has logging to lap top in real time. I have one too I used on the car. But hey to each his own enjoy!