Healey Silverstone Nash-Healey X5

X5 is the experimental prototype behind the Nash-Healey. Built on the lightweight Healey Silverstone platform, it was adapted to take Nash's 3.8-litre straight-six and a three-speed gearbox with Borg-Warner overdrive, a product of Donald Healey's 1949 deal with Nash-Kelvinator's George Mason.

Its competition record is unusually strong for a car of this age. Carrying the registration JWD 300 and race number 723, it ran the 1950 Mille Miglia with Donald and Geoffrey Healey, reportedly finishing 177th overall and ninth in class after oil-temperature problems and overdrive damage. It then returned to the works for more enveloping bodywork and cooling changes. At Le Mans that year, Duncan Hamilton and Tony Rolt took it to fourth overall and, according to contemporary histories, third in class.

The car is finished in green with black trim, is right-hand drive and shows 1,000 miles. The page lists five previous keepers and says the car comes with a guaranteed Mille Miglia entry. The price is on application.