Group R
Starting in 2008, a category of rally cars known as Group R were introduced as a rally only replacement to the Group A and Group N categories which were slowly phased out of eligibility. Cars were classified under one of six categories based on their engine capacity and type, wheelbase, and drivetrain. Group R cars still had to be homologated in Group A or N but have the relevant Group R extension approved in common with other rally formulae. As a result, older cars could reclassify under Group R subject to meeting criteria.