5. Jaguar XJ13
Back in the mid-60s Jaguar wanted to go racing, but they needed a new, modern car. And, it had to be far more advanced than the E-Type sports coupe they offered at the moment. That is why they conceived the secret XJ13 project. Jaguar wanted to produce a mid-engine supercar with a V12 unit in the back. Also, it had to have aerodynamic styling and sublime performance.
Unfortunately, they only completed one car, so the project never got off the ground. But once the race regulations changed, the XJ13 became obsolete even before they were ready to race it. They scraped the plans for a road-going homologation version. Unfortunately, the XJ13 became known as the best “what if” story in Jaguar’s history.