grand touring groups already used in rallying, and the production-derived special builds of Group 5 used in circuit racing. Group 5 had never been permitted in the World Rally Championship for Manufacturers. Homologation The number of cars required for homologation, 200, was just 4% of the other groups' requirement and half what was previously accepted in Group 4. As the homologation periods could be extended by producing only 10% of the initial requirement each subsequent year, 20 in Group B's case compared to 500 for A and N, the group made motorsport and the championships more accessible for car manufacturers before taking the group's technicalities and performance into account. 'Evolutions' could be included within the original homologation without needing to produce a new initial run, allowing manufacturers to tweak various aspects of their competing car within the requirement to produce only 20 'evolved' cars. Together, these homologation rules resulted in Group B 'homologation specials' (cars that were only produced to satisfy the group quota rather than for sales) extremely rare, if they continued to exist beyond presentation to FIA officials in the first place. Group B could be used to homologate production sports cars which could not be homologated in Group N or A, because they did not have four seats or were not produced in large enough numbers (e.g. cars like the Ferrari 308, the Porsche 911, etc.). Further, the low production requirement encouraged manufacturers to use space frame chassis instead of bodyshells typically used in most series-production road cars. Existing cars within Group 2, Group 3 and Group 4 homologation could be transferred to Group B, with many being automatically transferred by the FISA secretariat. Regulations Specific regulations Group B had few specific rules outside those covering all groups in Article 252 and 253, which covered such things as safety cages or parts defining a car like windscreens or rear view mirrors. Article 256 covered the specific regulations for Group B with 5 paragraphs over half a page. The first two paragraphs covered the definition, (Sports) Grand Touring Cars (with a minimum of two seats), and the homologation requirements. Fittings and modifications were inherited from those allowed in Group A. Rather than being restrictions, these covered those items (not) expected to be applied to a production car that would/wouldn't be expected on a competition car. Example include the removal of trims, soundproofing, HVAC systems, ignition systems or the