In relation to motorsport governed by the Fédération Internationale de l'Automobile, Group R refers to a set of regulations providing production-derived vehicles for rally competition.
Each VR extension is a set of homologated parts and modifications, designed and sold (as a kit or as a complete car) by the manufacturer.
As part of its structure, the Group R regulations have a provision for GT cars, known as R-GT.
No new models would be homologated under R4 regulations, with the FIA taking the long-term view that these would be replaced by bespoke kit cars.
The R4 Kit cars have a standard engine, four-wheel drive powertrain and suspension.