Automobili Lamborghini contacted Marcello Gandini to design the successor to the Lamborghini Countach, after the 25th Anniversary was created in a hurry, the Diablo was supposed to be ready by now, but design and testing took longer than expected and the Countach was redesigned to make it more up to date, hence the 25th Anniversary.
The Gandini design was very futuristic and aggressive looking, like the Countach was back in the Seventies, now the engine cover was made in glass, but in the early testing phase this arrangement didn't cool the engine enough, so the idea was abandoned.
The original Gandini design was later used for the Cizeta Moroder because at this time Automobili Lamborghini SpA was bought by Chrysler, and they changed the original design completely, two images on this site show in fact a rolling prototype that was half Gandini and half Chrysler designed, this way it was easy to compare both against each other, also this hybrid was compared to the Countach and a Ferrari TestaRossa on an enclosed part of the factory parking lot. This way it was easier to get an overall impression of the new Diablo super car compared to the rival TestaRossa.
Even Lee Iacocca was present at this comparison, the new Diablo didn't quite live up to the expectations and the Chrysler design was altered again, this time to something much closer to the final Diablo.
The famous dark gray P1 prototype pictured here was the first real Diablo or P132 as it was called inside the design department, this car was filled with measurement equipment and tested at the Nardi circuit for thousands of kilometers before it was retired at the factory where it still is located now, hidden away from the normal visitors, both orange prototypes are also still at the factory at this time. The first crash tests of the new Lamborghini Diablo were performed with P3, the third prototype built, finished in a bright blue, it managed the toughest crash tests without any problems.