"Internet connected entertainment system." Technologically very similar to OnStar and in the same family. OnStar/Entune/Sync/Uconnect are all in the same family just from different brands. OnStar is sort of the mother of the others. When GM came out with OnStar, I think most other manufacturers stayed away from the concept because they thought it was going to be a fad. As soon as it became clear that drivers were more interested in being users other automakers started incorporating as much internet connectivity they could (Entune/Sync/Uconnect/etc) and it was much easier to build it into the nav unit than to tie a standalone system into the car.

Calling the hack "using a digital-radio broadcast" is a little deceptive. That suggests they were using HD Radio signals when they were actually using internet connectivity to a radio on the CAN bus.