Federal and local law enforcement authorities are investigating what caused the Sunday night fire, which came after a series of attacks against Tesla in rebuke of its chief executive, Elon Musk.
Just remember: Tesla vehicles are surveillance machines, and the cops have access to facial recognition software, so I will not be surprised if whoever did this is caught.
Just a fun fact, the Tesla showrooms aren't owned by a third party like a dealership, they're owned by Tesla, so there's no "screwing over a local business owner" here.
Just for reference, while it has been edited, the comic is by Stan Kelly, The Onion's resident cartoonist. Kelly is fictional, a satirical stereotype of a right-wing newspaper cartoonist. His signatures are over-labelling everything, gratuitous self-inserts, and framing the wealthy/other advantaged groups as morally upstanding patriots unfairly victimized by their inferiors. The latter is usually accompanied by them crying a single tear.
All that to say, in the context of a Kelly comic, "Honest Tesla Salesman" is definitely meant ironically.