Well, I did the battery disconnect, and that didn't work.
Did the temp up and down button simultaneously, that didn't work.
Did the mute and tune buttons simultaneously, that didn't work.
Pulled fuses (dropped one in the engine bay, gotta hunt around for it), that didn't work.
Live chat woman wants me to call back stateside to talk to an agent, but that is gonna cost a kidney for the call charges.
Looks more and more like I am going to have to go to the local FIAT dealership. I'm sure it will be an adventure in language breakdowns, but maybe I'll get lucky and find out that my warranty carriers over from the U.S. to Europe.