Note: As of November 1, 2010, semi-annual updates of the single year Reference CDs will no longer be done. Instead, efforts will be concentrated on the combination 1966/1967 Chevelle Reference CD. Free updates will continue to be offered on the combination 1966/1967 Reference CD only. The single year Reference CDs will be revised at least once a year so you can still purchase a 1966 OR 1967 Chevelle Reference CD with confidence it will have the latest information.