A conviction for attempting to elude officers was improper where the court failed to properly instruct the jury regarding what constitutes a “distinctively marked” police vehicle. The California Supreme Court held that a trial court must, on its own initiative, instruct a jury that the statutory phrase “distinctively marked” requires that, in addition to a red light and siren, the peace officer’s vehicle have features that distinguish it from vehicles not used for law enforcement. Failure to so instruct the jury requires reversal.