Built in 1966, the Jaguar XJ13 was a racing prototype intended to be the model or precursor to an XJ that would eventually race at the 24 Hours of Le Mans. However, the emergence of the Ford GT and indifference by Jaguar management led to the XJ13 prototype becoming merely a one-off concoction.
However, the Jaguar XJ13 had plenty of interesting components and ideas that carried over to other race cars in subsequent decades:
Today, no one’s quite sure how much the Jaguar XJ13 is worth, but the owners once turned down a $7 million bid back in 1996—making it essentially a priceless collectible.