This is a whole story wrapped up in one short note. Sadly, we can't see the car in question, so we don't know how bad the parking that triggered this budding poet was, but it was sufficient for them to feel compelled to write about it. "Don't park like a tool," should be a permanent instruction that everyone on the road has to live by. The rest of it is a bonus.
Halfway through the message, our infuriated author starts to question whether the correct description of becoming angrier is 'get more mad,' or 'madder,' and so therefore blame the driver for their grammatical confusion. For reference, either one of them is fine. Just don't park so badly that you provoke anyone into questioning it. We like the way that the point introduced at the beginning is repeated at the end for effect.