You can resize as you wish, and add a double sided tape on the back, to be able to leave it on the car of your choice. Please, even if this plate can communicate your disagreement about how to park, this is intended mostly as a joke.
If you don't want to bother printing it in two colours, you can use a small sponge and some acrylic paint, as I did in the picture.
Enjoy!
The author remixed this model.