Contumacious

(adj.) Stubborn, obstinate, resistant to the rule of authority. This especially applies to disobedience to a mandate of the court.

Ex. "Contumacious Connie ripped up her speeding ticket, cackled, and put the pedal to the metal as soon as the police car was out of sight."

How I remember: Sounds like contemptuous, which has a similar meaning.