The Rainbow signalled Bertone's return, after nearly 15 years, to the Ferrari theme, this time with a freer interpretation. While the design of the Dino 308 GT4 represented a blend of sobriety and tradition, the Rainbow is an experiment in unconventio, page styling. In fact there were no intentions to put this model into production, and Bertone was able to interpret the theme without any constraints but functionality. The chassis was the same one used for the 308 GT4, teamed with the generous 250 Hp engine. Shortened by 10 cm, the chassis gives the vehicle a compact, aggressive feel. The prototype, which was presented at the 1976 Turin Motor Show, immediately stood out for its design peculiarities: first and foremost for the originality of the mechanical hood mechanism which stows the hood away behind the seats. This was a solution for the transformation from spider to coupé and back again in a context - that of the two-in-one car - that had long captured the imagination of designers the world over.
The unconventional Ferrari Rainbow represented faith in the automobile industry, in a period in Italian history which favoured stylistic conformity over experimentation into new design concepts.

source: Bertone