The EntityGroup name is probably not what you're after, since that name will be something like "DomainModel:Customer". The "entity set name" is probably what you're looking for. The entity set name is primarily a logical container for entities and is used by the Entity Framework. In DevForce, it's the entity set name which is used for the generated queries on the EntityManager (eg, "Vehicles") and a DefaultEntitySetName attribute also adorns generated entities. There is actually a subtle difference between a default entity set name for an entity type and the actual entity set name an instance of the type belongs to, but in most applications only the default entity set name is ever used. You can get this name through the EntityMetadata -
aVehicle.GetEntityMetadata().DefaultEntitySetName;
or
entityManager.MetadataStore.GetEntityMetadata(typeof(Vehicle)).DefaultEntitySetName;