Other than a couple of competition prepared cars, there was only ever one bespoke 308 GT4 Speciale produced in period. Built in 1976 and shown at that years Turin Salon, the Bertone-designed 308 GT4 Rainbow was a unique show car of questionable beauty but an intriguing concept nevertheless. Featuring lines clearly influenced by the Alfa Romeo 33/2 Stradale ‘Carabo’ seen back at 1968’s Turin Salon and Fiat’s X1-9 (both of which were designed by Bertone), the Rainbow was even more angular than the standard production car.
Is most interesting attribute (other than a chassis shortened by 100mm) was the retractable hard top that could be manually raised or lowered in a matter of seconds. However, this novel idea was never used on any subsequent models. Although intended as a concept car, collectors were afforded the chance of having their own Rainbow constructed by Bertone. But at the not insignificant cost of $200,000 in the late 1970’s (equivalent to around £500,000 today), there were unsurprisingly no takers and the solitary Rainbow remains the property of Bertone.