Technical regulations mandate that World Rally Cars must be built upon a production car with a minimum of 2500 units, based on a pre-existing Group A model, to which a number of modifications may be added, including but not limited to increasing (or decreasing) engine capacity to 2.0 litres, adding a turbocharger, four wheel drive, sequential gearbox and aerodynamic parts, and the Anti-Lag System on turbocharged engines.

The cars must also have a minimum weight of 1230kg.