The story starts at the Paris Salon in 1975, when the stunningly beautiful 308GTB – Ferrari's second V8-engined road car - was introduced marking a welcome return to Pininfarina styling following the Bertone-designed Dino 308GT4. Badged as a 'proper' Ferrari rather than a Dino, the newcomer had changed little mechanically apart from a reduction in wheelbase, retaining its predecessor's underpinnings and transversely mounted 3.0-litre V8 engine that now featured dry-sump lubrication. In road tune this superbly engineered power unit produced 255bhp, an output good enough to propel the car to a top speed of 150mph. Produced initially with glassfibre bodywork - the first time this material had been used for a production Ferrari - the Scaglietti-built 308 used steel exclusively after April 1977. The first steel bodied cars were manufactured in 1976, the change bringing with it a considerable weight penalty (of around 150kg) and consequent reduction in performance. Naturally, anyone wanting to race a 308GTB started out with the glassfibre version if they could.

For 1983, the FIA governing body of International motor sport introduced its new Group B regulations for major-league rallying. This innovation saw the specialist Italian conversion and preparation company of Michelotto develop a Group B-conforming variant of Ferrari's very popular and highly successful 308 Gran Turismo Berlinetta.

Since production of a full batch of 25 highly modified GTB Evoluzione cars was effectively out of the question, the specification of these Michelotto Group B machines incorporated as few changes as possible from the standard road car, while still providing clients with rally-winning potential. Michelotto's most significant development from its previous Group 4-converted cars was selection of the Quattrovalvole engine. Even so, the first Michelotto 308GTB emerged with the conventional and reliable two-valve head rather then the latest 'QV' power unit employed in the following three cars.

Ferrari 308 GTB Michelotto chassis serial no. 18869/engine no. 18869, offered by Bonhams at auction yesterday, was the first of four Group B configuration cars built by Michelotto from a total of 15 combined Group B and Group 4 cars that the company modified in period. It was first completed in February 1983 for the Pro Motor Sport team in Italy. Significantly this was the sole fibreglass bodied Group B Ferrari 308 GTB that Michelotto ever constructed.

During the subsequent 1983 rally season this car won many Italian national events, including the Valli Imperiesi Rally with Cambiaghi/Di Gennaro as driver and navigator; followed by the Sciacca Terme, Mari e Monti, 12 Hours of Campobello, Neborid and Proserpina events with Bronson/Di Prima in the hot seats. The car Ferrari 308 GTB GpB came 2nd in the 1983 'Championnat d'Italie des Rallyes' and won the 'Championnat de Sicile' with Bronson driving.

The cars successful career continued into 1984 as Zanini and Autet campaigned it in the Spanish Championship and won another six times, in the Criterium Guilleres, Sierra Morena, San Agustin, Luis de Baveria, Oviedo and Vasco Navarro Rallies. It also came 3rd in the 1984 Targa Florio.

These remarkably successful though relatively little publicized competition Ferraris featured Rose-jointed suspension and uprated Brembo brakes all round, new Canonica wheels and Pirelli tyres all as standard although routinely changed and updated during the vehicles' competitive careers. The forced substitution of Campagnolo wheels for narrower, more standard looking five-spoke Canonicas reduced track width compared to the sister Group 4 circuit-racing cars. Three of Michelotto's Group B 308s were fitted with QV 32-valve engines producing 310bhp at 8,000rpm, after this prototype (chassis 18869) had deployed the 288bhp two-valve motor. While the Group 4 variants used mechanical Kugelfischer fuel injection these Group B rally variants employed electronic Bosch K-Jetronic systems. These Group B variants weighed-in around 30kg heavier than their racing counterparts since they had to retain their stock glassfibre and steel body panelling.

As the first – and one of the most successful – of this rare quartet of Michelotto-built Ferrari 308GTBs this is a particular interesting and significant example of the Ferrari Berlinetta Competizione breed, in 1980s form. This car in fact has had just two owners from new until yesterday: Promotorsport and the vendor. Between 2009 and 2010 over €20,000 was spent to ensure that the car worked perfectly in all respects. The car was also offered with a selection of spare parts including: 6 Canonica wheel rims, Bosch injection, 2 sets of gear ratios and also came with French and Italian registration papers and a FIVA identity card.