Protip: Stick the cards on the passenger side rear-view mirror.
That way the driver won't notice them at first until they want to start driving, and then they have to get out of the car and walk around it to take it off.

I got one of these once and I thought it was hilarious because I drove a tiny Toyota Corolla at the time and I was parked in my normal work spot. I think it was from a douche who was parked in front of me, ironically in a giant pickup truck. I worked next to a PetsMart so I’m thinking they weren’t able load something into the back of their truck since they were backed into the spot. I kept that card for years and finally got rid of it when I got a new car. Ahh memories 😆