Motions under rules 1.1003 and 1.1004 and bills of exception under rule 1.1001 must be filed within fifteen days after filing of the verdict, report or decision with the clerk or discharge of a jury which failed to return a verdict, unless the court, for good cause shown and not ex parte, grants an additional time not to exceed 30 days. Resistances and replies may be filed and supporting briefs may be served as provided in rules 1.431(4) and 1.431(5).