It seems they are still out there, from the GT40 buried in a California Garage to this 1973 Ferrari Dino that was just listed in the Silverstone Auctions catalog, rare cars do still pop up from time to time. This one was found after its previous owner passed-away, the car is said to be hidden in its garage since 1975 with just two owners and only 13,932 miles showing on the odometer. The car was ordered in Verdi Pino with optional headlamp cover and Tan Interior. The interior features Ferrari 365GTB/4 seats, and are assumed to be installed at the factory when new.
How the then two year old Ferrari became sequestered into a garage until now is an interesting story. The last owner was a well-known motorcycle racer who liked to drive fast. After eluding the police in a short pursuit (they were after him for speeding), he raced home, parked the car in the garage and left there.
A leaky garage roof is said to be the cause for the current sorry condition of the bodywork, to me it looks like it was pulled out of some tall grass and shoved into a garage, but that is just my opinion. But like all things with enough money or some time with an English-Wheel it can be fixed.
Source: Silverstone Auctions