If you really want to get through to someone, forget about paper – write your message on their actual windshield. That way, they can’t throw away your note in disregard, but they’ll really have to think about what they did. At least this person was gracious enough to say “thanks,” after making this very reasonable request.
However, we’re a little baffled by this “dogg.” We’re used to it being a nickname of affection, like something one would say to their friend. We like this one because it’s concise and to the point. No fancy words, no long sob stories, no nothing. Just stop parking in my spot, dog. Thanks.