The relative risk of trying to do that is such that you are highly likely to injure someone. If no one got hurt in that type of attack, it’s by sheer luck.
Also, not a soul thinks people attacking unpurchased vehicles is a threat to escalate to hurting people.
Assume I somehow manage to blow up that obelisk in Washington DC. Would you consider this terrorism, even if no person got hurt?
The relative risk of trying to do that is such that you are highly likely to injure someone. If no one got hurt in that type of attack, it’s by sheer luck.
Also, not a soul thinks people attacking unpurchased vehicles is a threat to escalate to hurting people.
It’s a crime, but not everything is ‘terrorism’.