Speaking as someone who used to work in TV “journalism,” the media tend to trend on various stories. Remember the 18 million shark sightings a few years ago? It’s not like no one’s seen a shark before or since. It was just the fad story of the day, and so every time someone saw a fin CNN pounced.
“Hackers are after your car!” has just the sensationalist bent many “news” outlets are looking for, and so it’s one of the trending stories. Once people figure out that it can be done, but isn’t being done (rather like those “people can steal your garage door opener’s code!” stories of a decade or so ago) they’ll drop off the radar screen.