Group E features very few technical regulations. For safety regulations the articles refer to the category (I, II or III) the car is comparable with.
Group E features four different subclasses:
Category I: Vehicles comparable to Category I must comply with the homologation criteria of Group N, Group A or Group R and have at least 4 seats and their original structure must remain identifiable at any time.[2]
Category II-SH: Silhouette-type cars (Cars with the appearance of a large production car with 4 seats);
Category II-SC: Sports cars (Two seater competition cars, open or closed, built especially for competition);
Category II-SS: Single-seater track type cars of International Formula or Free Formula cars.