The news is that he was actually charged and convicted.

What other weapon might he have had available in some situation where he might get overcome with random vicious anger?
And in a way where the beginning of the violence is mostly accidental.

I don't think any other weapon than a car would have been able to bring him into this heinous deed.

That's not just unpopular, that's ridiculous and factually incorrect. First of all, nothing in the article mentions anything about premeditation or anything suggesting he would've murdered the guy by other means instead.

Second, it's well-established fact that the act of driving causes aggression that otherwise would not exist. Hell, Disney was making cartoons about it 75 years ago! The reason the behavior is specific to driving is that:

Anonymity inside a vehicle removes social cues that normally keep aggression in check, which is why calm people can turn hostile the moment they’re behind the wheel.