[emiliosic]

The 5G twist is pure BS. These cars (Circa 2016) have no modem that connects directly to the head-unit, and if they do are a separate module that's 3G only.

My theory is that the radio station sent some unicode characters on their RDS feed that crashes the system, it probably cached it (These head-units run on Linux, and is well known in some hacker circles), so now it's in some kind of loop. It won't be the first time that RDS feeds with some unusual combinations crash the head-units. If Mazda has a new firmware, these can be upgraded via the USB ports by booting into a recovery mode.