I would take a different approach than enums – I would make segment, fuel type and body type a separate entity (either a separate entity each, or one entity “Option” with a “Name” and “Price” attribute, depending on your requirements) with an association to the car entity. This allows your users to edit the available segments, fuel types and body types in the live application, and also allows you to add attributes to those specific entities (e.g. a price attribute, a description, etc.).