What design elements of the Piaggio Vespa have remained consistent over time, and why have they been retained?

Despite its many design changes over the years, several key design elements of the Piaggio Vespa have remained consistent, including its iconic shape, large wheels, and enclosed bodywork. These elements have been retained because they provide practical benefits, such as improved stability, protection from the elements, and ease of maneuverability. Additionally, they have become part of the Vespa's brand identity and are instantly recognizable to fans of the scooter.