Shop around local second-hand and vintage shops for old policeman’s hats. There used to be a place on Milwaukee in Wicker Park that sold them, but it’s been a long time since I lived there, so it may be closed. They’re around, anyway.
So once you’ve found a hat, take the checkered hat band, and hang that on your rear-view mirror. That’s the symbol that you’re either a cop or related to one, and means you’ll get special treatment. VoilĂ , free parking anywhere in Chicago.
Just hide it if/when you get pulled over, or you’ll cause yourself additional trouble. ;-)