Neither party is entitled to pretrial discovery in any action in municipal court, including refusal hearings held by a municipal court under s. 343.305 (9), except that if the defendant moves for pretrial discovery within 30 days after the initial appearance in person or by an attorney, the court may order that the defendant be allowed to inspect documents, including lists of names and addresses of witnesses, if available, and to test under s. 804.09, under such conditions as the court prescribes, any devices used by the plaintiff to determine whether a violation has been committed. The defendant may move for pretrial discovery at any other time upon a showing of cause for that discovery.