After Jaguar got world famous for its Le Mans wins, the successful 3.4 litre XK engine was also installed in its saloon cars and of course in the road-going version of the D-Type Le Mans car, the XK SS. 
 
Unfortunately, the factory where they were built was destroyed in a fire, after 16 cars were built. This was a financial disaster, as a bigger series was already planned - and sold.
 
These cars are now priceless.