What was on Dr Seuss’ license plate?

Theodore Geisel, aka Dr Suess, was born in Springfield, Massachusetts, but settled in California, the land of vanity license plates. He wanted a specific one, but it was unavailable. An ardent Seuss-lover with four children had already put GRINCH on the license plates and both sides of his RV. When that family moved to Iowa City, they released GRINCH back to the Geisels, with a note of apology for having hogged it for so long.