Ferrari 308 GT4 Rainbow (Bertone)
The Rainbow was based on the Dino 308 GT4, which Bertone had just designed. Neither the production 308GT4 or the Rainbow were much of a hit and most likely as a result did not design another car for Ferrari until their 2014 bankruptcy. It should be noted that Bertone created several classic designs including the Lamborghini Muira and Countach. Maybe Lambo just paid better.