It’s Revenge Time!
The sisters stuck the notes all over the car, including the tires. They had blue and white ones and had arranged them in the motif of a handicap sign.
With their revenge set, they went to sleep. But they woke up to a scream in the morning. Peeking out of their bedroom window, they saw the man yell and curse as he tugged on his hair. That was the last time he ever parked in that spot.