My paternal grandfather did something like that, but he was awesome.
He had his hip and then knee replaced in the late 80s and early 90s, so he had a handicap sticker on his car. Nothing bothered him more before OR after that than people parking in those spaces who didn't have permits and didn't need them. He used to put notes under some of their windshields but eventually just got business cards made that said, basically, 'You have parked in a designated handicap space without the appropriate permit. These are reserved, by law, for unfortunate people who need the proximity. This makes you illegal, rude, stupid, and an ASSHOLE.'
One day he put one under the windshield wiper of a standard Penis Compensation Truck and when Gramps was warming his own car up to go home, the owner of the truck came back and he was a big mean-looking guy who found the business card, read it, and threw a temper tantrum in the car park about it. My poor grandfather said he'd never felt quite so vindicated and scared at the same time.