Here is the opinion in Cressman v. Thompson.
Prior Tenth Circuit case here.
This appeal concerns an image stamped on the standard Oklahoma license plate ofa Native American shooting an arrow toward the sky. Appellant Keith Cressman objects to the image as a form of speech and wishes not to display it on his personal vehicles.But Oklahoma law imposes sanctions for covering up the image, and the state charges fees for specialty license plates without it—fees that Mr. Cressman does not want to pay. Because he must either display the image or pay additional fees, he argues that the state is compelling him to speak in violation of his First Amendment rights.
And the briefs:
Lower court materials here.